What does it mean if indicators related to red blood cells are reduced: total number, average volume, distribution index. The width of the distribution of red blood cells is increased: symptoms, additional diagnostics and interpretation, possible diseases, treatment What does it mean

During the study, various components of the blood are determined, or rather, their quantity.

Red blood cells are blood cells whose task is to:

• maintaining acid-base balance;
• removal of various amino acids from plasma;
• isotonic support;
• oxygen saturation;
• removal of carbon dioxide from cells and tissues of the body.

It is quite clear that disturbances in the quantitative content of red blood cells of various etiologies lead to various diseases of the human body as a whole. The main component of a red blood cell is hemoglobin.

Blood analysis

When testing blood in laboratory conditions, regardless of its purpose, the first step is to study the level of leukocytes, as well as hemoglobin saturation:

• with an increased content of leukocytes, blockage of small vessels may occur,
• If there are insufficient numbers of red blood cells, oxygen starvation may occur.

When analyzing, concepts such as the average volume of erythrocytes, hemoglobin content in one erythrocyte, and hemoglobin concentration are distinguished. Also an important indicator is the width of the distribution of red blood cells, whether it is increased.

Increased distribution width of red blood cells

The width of the distribution in a healthy person is equal to 11.5 to 14.5 percent. When this indicator increases, that is, when the distribution width increases, the red blood cells differ greatly from each other in size. The increased size of red blood cells shortens their lifespan, which of course negatively affects total erythrocytes in the blood.

As is known, with a fairly large destruction of red blood cells, as a result of which a large amount of iron and the yellow pigment bilirubin are formed in the blood, which enters the liver for further processing. The liver, under this load, cannot fully cope with the processing of iron, which also has an adverse effect on human health. Also, the width of the distribution of red blood cells, when increased, affects the work of the spleen, leading it to increase in size, due to the fact that the spleen removes “non-working” red blood cells from the body and releases new ones into the blood.

This increased functionality of the spleen can affect the organs nearby. Due to a significant increase, the latter can crush the stomach and intestines. With pressure on the lung, the development of various types of upper respiratory tract diseases is also possible.

With an increased distribution width of erythrocytes, one can, first of all, judge a disease called “iron deficiency anemia.” This disease is the most common among anemias. At different stages, the width of the distribution of erythrocytes is not increased equally. In the initial stages of the disease, the density indicator may be normal, but the hemoglobin content may be reduced.

As the disease progresses, the width of the distribution of red blood cells increases, that is, individual red blood cells increase in size. On the contrary, the hemoglobin content in red blood cells decreases, sometimes to a critical level. Treatment of this type of anemia primarily consists of normalizing hemoglobin levels and its characteristics. Treatment mainly occurs through medication using drugs with a high iron content.

As the width of the distribution of red blood cells increases, heterogeneity of red blood cells is often noticed, that is, red blood cells that differ greatly in size are observed in the blood. Also, the reasons for the increase in the width of distribution of erythrocytes can be various kinds of chronic liver diseases, lack of vitamin B12, various types of neoplasms, cancer and other boards.

Symptoms of increased red blood cell distribution width

When increased red blood cell distribution width develops, a variety of manifestations may occur.

For example, since in in this case There is a significant effect on the liver and spleen, yellowing of the skin and an increase in body temperature may appear. As with any disease, sweating, loss of strength, drowsiness and fast fatiguability. From the outside nervous system For a person, both excitation and, conversely, more renounced states are possible. In any case, the symptoms cannot be specifically described, since changes in red blood cells affect many organs.

Consequently, a violation of the width of the distribution of erythrocytes can lead to diseases of varying nature and severity, since the human body is a rather complex system, with a number of interconnected organs and systems. Abnormal functioning of one of them can lead to a malfunction of the body as a whole.

Red blood cell distribution width (RDW) is increased

If the RDW blood index (red blood cell distribution width) is higher than normal, this means that the risk of anemia is increased and a person with such blood values ​​should visit a hematologist as soon as possible. Elevated RDW values ​​indicate, in addition to anemia, also an increased risk of malignant blood pathologies caused by bone marrow diseases.

Determination of the distribution width of red blood cells

The RDW value shows the heterogeneity (diversity) of red blood cells (Er) in size. Normally, the average erythrocyte volume (MCV) in an adult is from 80 fl dofl (µm 3). The appearance of small erythrocytes (microcytes) and/or large Er (macrocytes) is noted in blood pathologies.

Various types of anemia and myeloproliferative diseases are accompanied by changes in the size of red blood cells. Transformed Er appears in the blood, the sizes of which are smaller or larger than normal.

The range of Er size values ​​from the smallest microcytes to the largest macrocytes is called the width of the erythrocyte volume distribution.

The following erythrocyte indices have clinical significance and are necessary for diagnosing anemia and bone marrow pathologies:

• RDW-CV is the coefficient of variation (CV) of Er dimensions;
• RDW-SD - means the relative width of the distribution of red blood cells by volume.

What the RDW-CV shows

The RDW-CV index is measured as a percentage and is calculated based on the Er distribution width graph. The coefficient of variation is calculated in the following way:

RDW-CV = SD*100%/MCV.

The calculated distribution of the width of CV erythrocytes depends on the average size of erythrocytes; if RDW-CV is increased, this may mean an increase in the number of macrocytes and an increase in microcytes.

The SD value is the deviation of the Er value from the average value to the greater and lesser sides from the midline on the graph.

Changes in this index can be monitored using the erythrocyte histogram.

• As the coefficient of variation increases, the histogram shift increases in right side when a significant number of macrocytes appear.
• The predominant content of microcytes leads to a shift of the histogram to the left, towards smaller values ​​of erythrocyte cells.

RDW-SD Index

The hematology analyzer calculates the RDW-SD indicator automatically and produces a ready-made result based on the red blood cell histogram. This blood index is measured in fl (µm 3), and means the difference between the largest and smallest Er.

And if the hematology analyzer calculates RDW-CV using a formula, then to calculate RDW-SD a red blood cell (RBC) histogram is needed. On it, along the OX axis the Er values, measured in fl, are indicated, on the OY axis - the total number of erythrocytes in percent.

The RDW-SD value is numerically equal to the length of the straight line segment on the OX axis drawn on the erythrocyte histogram at the 20% level along the OY axis.

RDW standards

Normally, the relative spread width Er RDW-SD is constant and amounts to 37 – 47 fl. Pathological deviation erythrocyte sizes from normal or anisocytosis is noted when RDW-SD values ​​are more than 60 fL.

On the histogram, this means that the value of the relative width of the volume distribution is increased if the spread of erythrocytes in the sizes of the smallest and largest Er on a straight line drawn along the OY axis at the level of 20% is greater than 60 fl.

Norms for the coefficient of variation of erythrocytes RDW-CV - volume distribution width, table.

The normal distribution width of erythrocyte cells changes during pregnancy and is by trimester:

RDW-SD is different hypersensitivity to the appearance of microcytes. RDW-CV exhibits particular sensitivity to anisocytosis, the occurrence of deviations in the size of Er blood.

The level of anisocytosis of a blood sample reflects the heterogeneity (variability) of red blood cells in size.

There are different degrees of anisocytosis:

Analysis transcript

Red blood cell RDW indices obtained when processing a sample with hematological automatic analyzers are necessary for early diagnosis:

• deficiency of Fe, folate, vitamin B12;
• types of anemia;
• morphology of erythrocytes - structural features and sizes;
• myeloproliferative diseases affecting the bone marrow.

Decoding of the analysis data is carried out taking into account all erythrocyte indices. When interpreting the distribution width Er, the MCV value is of particular importance.

Raising RDW

The index of distribution of erythrocytes by volume is increased in anemia caused by B12 deficiency, and this means that the number of macroerythrocytes in the blood is increased, and the histogram is shifted to the right.

If the volume distribution width is increased, but the erythrocyte index such as MCV is increased, we can assume:

• hemolytic anemia;
• B12 deficiency;
• cold agglutination is a disease associated with the appearance in the blood of antibodies that glue red blood cells to each other in response to the action of cold.

Increased RDW (wide distribution of erythrocytes) and increased MCV in liver diseases, anemia caused by lack of vitamin B9.

An increase in the distribution width with a reduced index of average erythrocyte volume is observed in diseases:

Increasing the spread width Er at normal MCV indicators may indicate:

• for a lack of vitamins B9 and B12;
• on the development of iron deficiency.

With increased values ​​of the distribution width in the blood, accelerated destruction of red blood cells occurs, which is why the liver and spleen work at the limit of their capabilities. This leads to disruption of their functions, which manifests itself:

• the appearance of excess bilirubin;
• high Fe content;
• enlarged spleen.

Lower RDW

A decrease in the volume distribution width of Er means that there are cells of similar sizes in the blood. The boundaries of the spread of the RDW-CV value are narrowed in the following cases:

• oncological diseases - myeloma, leukemia;
• hemolysis - destruction of red blood cells;
• injuries with significant blood loss;
• deficiency of iron, B vitamins.

When RDW-CV decreases to 10.2%, macrocytic or microcytic anemia is suggested. In these forms of the disease, red blood cells are predominantly increased or decreased in size compared to the norm.

Microcytic anemias include iron deficiency, iron saturation, and iron redistribution. Macrocytic anemia develops with hypothyroidism, pregnancy, liver disease, hematopoietic disorders in the bone marrow, lack of copper, vitamins B12, and folic acid.

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Red blood cell distribution width (RDW index): what is it, normal, increased and decreased

To determine different populations of red blood cells, an indicator (erythrocyte index) is used - the width of the distribution of erythrocytes - RDW or the degree of anisocytosis of erythrocytes, which is included in the list of all components of the general blood test (CBC), that is, this parameter, as a rule, is not assigned independently and not tested in the laboratory.

So what does a red blood cell index like RDW mean, what information does it provide to specialists and what is it used for?

Distribution of red blood cells by volume

If you examine the red blood cells present in the blood of a patient suffering from a certain hematological pathology under a microscope, you will find that the red blood cells (Er) are not all the same in volume. Among all the anucleate biconcave forms, there may be cells that differ significantly in size from normal red blood cells:

• Large cells are macrocytes;
• Just giants - megalocites;
• Lilliputian cells called microcytes.

And here you don’t have to be a specialist in this field to understand that red blood elements that have changed their volume will not be able to fully perform their tasks. physiological functions(transfer of oxygen and nutrients, regulation of water-salt metabolism and acid-base balance, participation in blood clotting, etc.), which, naturally, will affect the overall health of the body.

Meanwhile, one should not attach too much importance if ugly forms are present in single copies; it is another matter if they claim an equal position with normal red blood cells. In order to find out how many bizarrely shaped red blood cells are in the general population, characteristic of a particular type of anemia, the width of the distribution of red blood cells (red blood cell index RDW) is calculated.

Many laboratory diagnosticians and hematologists take RDW as the coefficient of variation, indicating how much the mean red blood cell volume (MCV) deviates from the generally accepted norm, and calculate it using the formula:

where SD denotes the standard deviation of the average volume of red blood cells, and the MCV index corresponds to their average volume.

Can you always trust the norm?

The range of normal values ​​for the distribution of red blood cells by volume varies from 11.5 to 14.5% (in children under six months of age, the norm is, in general, noticeably different and ranges from 14% to 18.7%, although from 6 months the values ​​of the indicator are already begin to strive for the adult norm).

An increased RDW in a blood test indicates the degree of heterogeneity (heterogeneity) of the red cell populations in the blood or indicates the presence of multiple populations of blood cells in the sample, as occurs, for example, after a recent blood transfusion.

It is unlikely that the term “reduced RDW value” can be used when calculating the width of the distribution of erythrocytes, since this option reflects the norm, and therefore cannot be taken as a laboratory indicator characterizing some phenomenon unusual for these blood elements. The fewer unnatural forms (due to an increase or decrease in volume) of red blood cells in the blood, the more representatives of the population for this characteristic are within the normal digital values. And yet, if this happens (RDW - reduced), then most likely the analyzer made a mistake and in order to correct this mistake, the patient will have to provide a finger for a puncture again, and the laboratory staff will have to calibrate the device.

In addition, it should be taken into account that RDW, which is within the normal range, is not always proof of complete health, because in some cases the indicator of red blood cell distribution by volume is not increased, but clinical manifestations and laboratory tests confirm the presence of the disease (anemia).

Increased RDW ratio

An increased index is a quite suitable indicator even for the differential diagnosis of certain types of anemia; it allows one to distinguish between the following forms:

1. Megaloblastic and macrocytic, a typical representative is B12/folate/deficiency anemia. In the blood test: hyperchromia, average Er volume - above 160 fL, cell diameter more than 12 microns, RDW - increased (anisocytosis), different shape red blood cells (poikilocytosis);
2. Normocytic: aplastic anemia, as well as anemia caused by chronic pathology (tuberculosis, pyelonephritis, collagenosis, liver disease), malignant process or caused by dysfunction of the endocrine system;
3. Microcytic (iron deficiency anemia, in the blood test: hypochromia, anisocytosis towards microcytosis).

True, in such cases, in addition to RDW, diagnosis is also based on another erythrocyte index - MCV, which characterizes the red blood cell as a normocyte (at 80 x / l - 100 x / l or 80 - 100 femtoliters), microcyte (at - below 80 fl), macrocyte (if the average volume is more than 100 fl).

In addition, when testing blood samples to calculate the values ​​of erythrocyte indices (including RDW), it is very important to compare the results obtained with a histogram of erythrocytes, which, after completing its work, is usually produced by modern hematological systems with software.

Thus, an increased RDW with mean erythrocyte volume (MCV) values ​​above 100 fL may indicate the following pathological conditions:

• IDA (iron deficiency anemia) is the most common anemic condition (IDA accounts for up to 80% of the entire group of diseases of this kind)
• Sideroblastic anemia (heterogeneous group of hypochromic microcytic anemias);
• Macrocytic and megaloblastic anemia;
• Myelodysplastic syndromes, which are a hematological pathology that unites a group of heterogeneous diseases with characteristic signs of a decrease in the number of individual populations of blood cellular elements (cytopenia) and a clonal disorder of hematopoiesis in the bone marrow (dysplasia). Myelodysplastic syndrome has a high risk of transformation into a malignant process;
• Bone marrow metaplasia;
• Metastases of malignant tumors to the bone marrow.

Obviously, for a certain range of pathological conditions, calculating the width of the distribution of erythrocytes has a very important diagnostic value.

Why is RDW a new indicator for patients?

Previously, until automated hematological systems entered the daily life of laboratory services, the degree of anisocytosis was determined visually by viewing a smear using optical equipment. And the red blood cell distribution width was not called RDW and was not calculated by a device designed for automatic hematological analysis. The calculation was made using a different method - using the Price-Jones curve, which, as it later turned out, did not coincide with the erythrocytometric curves performed by a “smart” machine with maximum accuracy, but it took a lot of effort and time from doctors and laboratory technicians to conduct the study. Now, having placed a sample in a “smart” device, no one asks him one question - to work only on a separate test. The analyzer will simply calculate everything that is provided for by the program and included in it, which is why patients began to see new indicators that were not there at all when processing samples manually.

And such studies were previously of interest mainly to hematologists to clarify the nature of anemia, who, if necessary, contacted the laboratory with a note in the direction: to conduct a morphological study of red blood cells, calculate and present graphically (erythrocytometric Price-Jones curve) the ratio of the number of red cells with different diameters. Of course, not all blood samples were subjected to such testing, but only samples taken from specific patients. Now, in principle, nothing has changed; a separate circle of specialists will most likely be interested in this indicator. Well, since RDW is present in the blood test, then patients have the right to ask questions.

Currently, the calculation of RDW in blood analysis is successfully performed by an automatic hematology analyzer, which quietly, quickly and efficiently solves the problem. And makes RDW to everyone.

The width of the distribution of red blood cells is increased - what is it?

When donating blood for general analysis in clinics, people know approximately that laboratory assistants, in the process of research, determine the number of certain cells or blood cells in the body of the person being examined. To be more precise, 50-60% of blood is liquid plasma, and platelets, erythrocytes and leukocytes are suspended formed elements, which account for, respectively, from 40 to 50% of general composition blood.

As for red blood cells, these red cells are:

• regulate acid-base balance;
• adsorb lipids and amino acids from plasma;
• maintain isotonia;
• carry oxygen to tissues from the lungs and return carbon dioxide to the lungs from tissues.

Therefore, it is clear that a violation of the number of red blood cells in the blood leads to various kinds of diseases in humans.

The main component of the red blood cell is hemoglobin, a special respiratory pigment.

General blood analysis

Thus, when a general blood test is taken from a patient, the total number of red blood cells and hemoglobin concentration are checked, among other things.

• An increased content of red blood cells leads to blockage of capillaries;
• A low number of red cells will lead to oxygen starvation.

In this case, it is customary to distinguish the following erythrocyte indices:

• Average erythrocyte volume - MCV;
• The average hemoglobin content in one red blood cell is MCH;
• Average hemoglobin concentration – MCHC.

These parameters are determined by a special device – a hematology analyzer. It also shows another blood parameter - red blood cell distribution width - RDW.

The width of the distribution of red blood cells is measured as a percentage and the norm is considered to be from 11.5 to 14.5.

More about RDW

So, it happens that the width of the distribution of erythrocytes is increased or, on the contrary, almost zero. This means that the red blood cells present in the blood are too different from each other in size, and in the zero variant they are almost the same. In the first case, there is anisocytosis, which, by the way, does not have an independent character, i.e. necessarily caused by some reason. A decrease in the size of red blood cells is a slow process of blood formation and the appearance of degenerative red cells. And an increase in size is manifested by an indicator of their increased production. And so, when there are too many micro- and macroelectrocytes in the blood, the body sounds the alarm.

Diagnosis of diseases

Most often, the doctor diagnoses such a patient with anemia. In this case, microanisocytosis appears due to hypochromic anemia, and macroanisocytosis appears due to hypochromic anemia. pernicious anemia. But in both cases the width of the distribution of red blood cells is increased. And both options require long-term treatment, as a result of which new, normal blood cells are formed. By the way, there are a number of other diseases in which anisocytosis is observed. If this is microcytosis, then the following are possible:

If this is macrocytosis, then the following cannot be excluded:

• Diffuse liver damage;
• Alcoholism;
• Folate deficiency anemia.

In any case, the final, only correct diagnosis will be made by a specialist, and therefore a visit to the doctor is simply necessary. Because a competent doctor can make the correct conclusion based on tests. More than once we watched as a young mother ran down the corridor in panicked horror with test results in her hands and wailed, not even suspecting that some parameters in a child’s blood tests were even higher than those of an adult.

It is interesting that the red blood cells of newborns are larger in size than those of their parents.

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Why the distribution width of red blood cells is increased and treatment

Deviation of indicators from the norm indicates pathological processes, occurring in the body. When performing an analysis, it may be revealed that the width of the distribution of red blood cells is increased. What does this mean?

The components of blood are:

Red cells

Red blood cells are blood cells that give it a characteristic color. U healthy people They are the same in volume and shape. Red cells perform the following tasks:

• ensuring a normal acid-base environment;
• oxygen saturation;
• isotonic support;
• removal of carbon dioxide from tissues.

The proper functioning of red cells depends on their volume in the blood.

A disturbance in the level of red blood cells is caused by the development of some pathology in the body.

The main component of red cells is hemoglobin.

Blood test

At laboratory analysis blood, first of all, the number of leukocytes and hemoglobin level are determined:

• with an increased level of leukocytes, there may be blockage of small vessels;
• at insufficient volume red cells are deficient in oxygen.

An important indicator of blood testing is the width of the distribution of red blood cells. In healthy people, the percentage ranges from 11.5 to 14.5. As this level increases, red blood cells globally differ in size among themselves. Increased parameters of red cells reduce their vital activity, which in itself negatively affects the total number of red blood cells.

With a sufficiently large-scale destruction of red cells, a large volume of iron and the yellow pigment bilirubin are concentrated in the blood, which enters the liver for subsequent processing. Under the influence of such a load, she cannot fully cope with it, which negatively affects a person’s well-being and health. Also, with an increase in the distribution of red cells, there is a negative impact on the functioning of the spleen. It increases in parameters due to the fact that it cleanses the body of “broken” red blood cells and releases new cells into the blood.

Such activity of the spleen can adversely affect neighboring organs. As it increases, pressure occurs on the intestines, stomach, and lungs.

When an increase in the width of the distribution of red cells is determined, then first of all, experts judge a pathology called “iron deficiency anemia.” This disease is the most common. At different stages the level of width is increased in different ways. On initial stage pathological course, the density coefficient may correspond to the norm, and the hemoglobin content may be reduced.

As the disease progresses, the width of the cell distribution increases, that is, some red blood cells become larger in parameters. On the contrary, the hemoglobin level in cells drops, sometimes even to a critical level. Treatment of this type of pathology is associated with normalization of its level. Therapy mainly involves the use of medications containing large amounts of iron.

An increase in RDW in adults, children, and pregnancy can occur when anemia develops, the body lacks vitamins, or there are liver pathologies.

If there is an increase in cell distribution width, red blood cell heterogeneity is often observed. There are bodies in the blood that differ significantly in size. Also, factors in this pathological course may be various chronic liver diseases, deficiency of vitamin B12, any neoplasms, cancerous tumors And so on.

In an adult, a blood sample is taken from a vein in the morning on an empty stomach. A sample is usually taken from a child's finger.

Symptoms

When the relative distribution width of red blood cells increases, various symptoms may appear.

For example, yellowing of the skin is observed, since in this case there is a serious impact on the functioning of the liver and spleen, and an increase in temperature. As with many other diseases, the patient's sweating increases, the person becomes drowsy, quickly tired, and weak. Due to the effect on the nervous system, the patient experiences frequent mood swings: excitement suddenly changes to renounced behavior. In each situation, the symptoms cannot be accurately described, since changes in red blood cells affect many human organs.

It follows from this that a change in the width of the distribution of bodies sometimes becomes the cause of pathologies of various nature and severity of development, since the body is a rather complex system with a line of interconnected organs. Improper functioning of any of them can cause a malfunction of the entire body.

The relative width of the distribution of erythrocytes by volume is increased or decreased

As a result of blood sampling, in order to exclude a particular disease in a person, doctors carry out necessary research to identify pathologies in the collected plasma and its constituent cellular elements in the form of erythrocytes, leukocytes and platelets. Described elements for performing your normal function defined by typical sizes, volumes (CV) and shapes. Therefore, any change in these indicators can affect the vital activity and active functioning of cells and ultimately lead to various changes in homeostasis. Therefore, to be able to correctly evaluate the cells being described, an indicator was developed in the form of a certain index indicating the width of the distribution of red blood cells (rdw).

Using such an erythrocyte index, it is possible to determine in the hematopoietic system the presence of red blood cells of different volumes, their distribution and the scale of differences between the largest and smallest elements described. Often, the so-called blood cells have a homogeneous structure and a designated single volume, but over time or as a result of the emergence of certain pathologies in a person, some discrepancies may be observed between the cells.

Moreover, in nature there are diseases that can be detected at an early stage of their manifestation only through a blood test for the width of the distribution of erythrocytes - RDW CV.

What determines the width of the distribution of red blood cells

And so the term described is determined by a certain index, the use of which allows doctors to obtain information about the actual distribution of blood cells of various volumes and shapes. That is, when decoding this index, you can obtain information about the percentage of red blood cells in the hematopoietic system - the size and volume of these cells, which can be increased or decreased.

To fill existing blood cells with oxygen, blood particles need to have a secure passage even into the smallest vessels human body. That is why, both physiologically and in size, the described bodies must fit the so-called vascular openings.

If excessively large or very small described elements are formed in the hematopoietic system, this leads to all sorts of changes in the described structural units of the human body. As a result, a person needs to designate the cellular component of plasma by using an indicator in the form of RDW CV.

How is the study carried out and what is the norm for the width of the distribution of red blood cells?

Blood for the calculated distribution of the described cells is taken for research in view of:

• Planned analysis;
• Necessary diagnosis of certain pathological phenomena;
• Surgical intervention in the human body;
• The origin of the various etiologies of anemia.

It is precisely the last described pathological conditions that are a frequently encountered indicator indicating the need for certain blood tests. Moreover, the most modern methods of collecting blood from a person make it possible to carry out any examination of the hematopoietic system quite quickly and with high quality, giving a correct assessment of the condition of the red blood cells themselves.

The results of the tests will be negative if the described indicators are normal, and positive if high level R.D.W. And only with a repeated examination will the physician be able to explain to the patient the pattern and reasons for this increase, since it is impossible to establish a reliable diagnosis using a single blood sample. For example, after any operation, the described index is usually due to an increased level of RDW.

Blood for testing can be taken from a vein in an adult patient, or from a finger in children. When taking the test itself, the recommended last meal should be taken 7-8 hours before the test itself.

To determine the norm of the indicator, the following are taken into account: age, gender and certain physiological processes occurring in the human body. For infants aged 0 to one year, the determining value of the norm can be considered an indicator ranging from 11.5 to 18.7%.

After the first year of life, the digital value of the index begins to approach the norm from 11.5 to 14.5%. For representatives of the fairer sex, the upper indicator can shift and reach a digital value of 15.5%, as a result of hormonal changes in the body:

• During pregnancy;
• During lactation;
• When using contraceptive means;
• In view of the onset of menopause.

Important! Blood sampling should be done on an empty stomach. Before the study, you cannot use any medications internally.

In the process of in-depth study of the characteristics of the distribution index of the described cells, it is customary to consider the following two values ​​in the form:

• RDW (SD) – determining indicator standard view deviations from the norm are determined by femtoliters and indications of the quantitative difference between large and small cells;
• RDW (SV) - indicates the existing differences in the volumetric value of the described elements and the established average indicators. It is revealed by the percentage correlation of cells that have succumbed to deformation to the mass of all red blood cells.

Reasons for the increase

The described coefficient of blood cells is higher than normal with an increase in the percentage correlation between small and enlarged cells, in relation to the described elements having sufficient volume. Due to the so-called redistribution of iron-containing protein, which is the basis of blood cells, the smallest number of them in the body begins to be synthesized, which subsequently leads to the manifestation of various anemias, to anisocytosis - when the main part of the cells have characteristic differences from each other.

According to the above, the main feature of such bodies is their sufficient size, as well as the period of life. As a result of their death, a decent amount of bilirubin is released, which has a very bad effect on all organs of the human body.

The coefficient that distributes blood cells by volume can be high, since there are:

• Lack of components in the body such as iron, folic acid, vitamins belonging to group “B”. Such a condition may, not without reason, give a chance for the development of a disease such as anisocytosis, in which an increase in this index of elements of the hematopoietic system occurs;
• Oncological diseases leading to the formation of red blood cells of various sizes and volumes in the hematopoietic system;
• Intoxication with chemical elements in the form of heavy metals (such as lead).

All of the above signs of disease should be stopped with the use of professional therapy. Otherwise, they will seriously harm the body and lead to death.

Reasons for the decrease in the indicator

When RDW - CV is below normal, the existing elements of the hematopoietic system are indicated by the same sizes without any differences in cell volume. When the volume indicator under consideration is reduced, doctors most often diagnose a condition in the form of microcytosis, in which the elements present in the blood, indicated by small sizes, cannot fully saturate the tissues of the human body with oxygen.

Also, when the indicator decreases, a disease accompanied by the unification of the main blood elements of small sizes often occurs, along with a reduced RDW rate in the form of thalassemia. Which refers to diseases of a hereditary nature, and manifests itself as disturbances in the processes of synthesis of iron-containing protein chains, with reduced activation in relation to oxygen. In light of this, plasma is no longer able to participate in the process of gas exchange in a normal and adequate manner, which ultimately leads to a change in the functioning of existing organs in humans.

This disease is also characterized by changes in the morphological properties of blood cells, with inhibition of their growth and decreased activity. The clinical picture of this disease is due to deformation cranium human, the growth of organs, such as the liver and spleen, as well as the icteric color of the skin.

Also, with a reduced ratio of such blood cells, a disease called microspheracytosis, which is a hereditary disease, can develop. When such a disease appears in the hematopoietic system, there is an increase in the small size, a certain shape of red blood cells, along with a decrease in the RDW coefficient, due to their insufficient vital activity. As a result, intravascular cell death occurs and so-called hemolysis develops.

In this condition, a person feels weakness, anemia, and jaundice characteristic of this condition, along with changes in the activity of all organs of the human body.

If any of the above symptoms occur, you should immediately seek medical help and, for your own safety, carry out full examination the whole body. Only in this way can you protect yourself, thereby preventing one or another possible already emerging disease.

The red blood cell distribution index is an important blood test indicator. In medicine, there is a list of diseases whose occurrence can be determined in the early stages. For this, an RDW blood test is performed, in which attention is paid to this distribution index, since pathologies that exist in the body are the causative agent of an increase in the number of red blood cells.

Such cells are a basic component in blood circulation and are responsible for the red color of blood. Their function is to supply oxygen to every organ of the human body. A person who has good health, distinguish red blood cells that are equal in shape, consistency and color.

The size of red blood cells does not have any effect on their functioning, which cannot be said about the increase in red blood cell volume. The metric that indicates this is called MCV. If a person is healthy, then this indicator is small and is located in the minimum limit. Fluctuations within the limit from the smallest red blood cell to the largest are called the breadth of red blood cell distribution. When diagnosing, this latitude is designated by the abbreviation RDW.

What do the indices show?

There are several indices that focus on a variety of indicators. Their study becomes the most important part of the general blood test, and it is not done separately from this analysis. Indices are sorted by red blood cell distribution:

• red blood cell size, hemoglobin content and its mean volume (MCV);
• hemoglobin content in erythrocyte (average value) (MCNC);
• mean hemoglobin concentration (MCHC);
• distribution by red blood cell size (RDW).

Analysis of RDW indicator and general blood test

RDW is examined through a clinical blood test. Such an examination can be planned and preventive, or aimed at diagnosing specific diseases. Blood diagnostics are carried out before surgical operations; repeat tests are also taken after a course of therapy to eliminate anemia.

If a blood test is performed, the RDW indicator is examined together with the MCV. This alliance assists in finding out what type of microcentral anemia is present in the body using differentiation of characteristics. If a low MCV level corresponds to the average RDW index, then this indicates the detection of diseases such as:

• thalassemia;
• blood transfusion;
• hemorrhage.

In addition, the RDW index may appear in the presence of low-quality formations and during chemotherapy courses. If the RDW indicator increases at a reduced MCV level, this indicates problems such as:

• iron deficiency;
• red blood cell fragmentation;
• thalassemia;
• presence of anisotropy.

A situation in which the MCV is high and the RDW is at an average level indicates that there is something wrong with the liver in the body. And if both parameters are too high, then various types of anemia are diagnosed. In addition, such indicators are a consequence of chemotherapy.

Formula for determining RDW

The index is calculated using a medical formula, which pays attention to the number of red cells and the deviation of the number of red blood cells. This index is measured as a percentage. The norm is a figure not exceeding 15 percent.

“Increased width of distribution of red blood cells” – you can often hear this phrase from doctors, the meaning of which we do not always understand. In healthy people, this value ranges from 11 to 14 percent. When the indicator increases and the distribution width is exceeded, the red blood cells begin to differ from each other in size. Those red blood cells that are larger than others live less and this does not have the best effect on the number of red blood cells in your blood.

If red blood cells disappear from your body in large volumes, then the amount of iron and bilirubin in the body increases, which enters the liver, and it begins to work under heavy load. There may come a time when the liver can no longer cope with such volumes of iron. This will be reflected in the condition of your body. In addition, the red blood cell distribution index is reflected in the work of the spleen: it increases in size and destroys non-working red blood cells, and releases new ones into the blood. But with such active functioning of the spleen, problems may arise with gastrointestinal tract and respiratory system. After all, increasing in volume, the spleen will put pressure on these organs.

The most common disease with an increase in the red blood cell index is iron deficiency anemia. Indicators vary depending on the stage of the disease. At the very beginning of the disease, the width index is increased, red blood cells are characterized by heterogeneity, and other indicators remain completely normal. Only hemoglobin remains elevated.

As the disease spreads, the distribution index increases as some of the red blood cells increase in size. And hemoglobin is reduced to critical levels. Therefore, treatment mainly consists of normalizing hemoglobin levels. For this purpose, iron-containing preparations are used.

The concept of heterogeneity of erythrocytes is used in cases where they differ greatly in size. In addition, a high index can result in deficiencies of certain vitamins and emerging tumors.

How to know if your readings are up

When the disease develops and the red blood cell ratio increases, you should pay attention to a number of symptoms:

• yellowing of the skin (results from stress on the liver and spleen);
• high body temperature;
• prostration;
• increased sweating;
• severe fatigue, craving for sleep;
• problems of the nervous system: from excitement to depressed states.

It follows from this that defects in the value of the erythrocyte distribution index can be caused by many diseases that differ in nature and severity. The human body is a complex system, and the insufficiently correct functioning of one organ can lead to illness in others along the chain.

The high pace of development of medicine has led to the fact that for the diagnosis of red blood cells, the most powerful analyzers are used, which determine the composition of the blood according to various parameters and with minimal error. If the analyzer does not detect any abnormalities in your blood, then you will not need a second examination. And if the level is even slightly elevated, then a repeat analysis is required for a more detailed diagnosis.

There's no reason to be sad

If you receive analysis results with a disappointing figure increased indicators, no need to panic. There are a number of cases in which this excess is not a pathology:

1. If the test was done after you had a blood transfusion.
2. After surgery. In such cases, the plasma goes through an adaptation period.

Do not try to diagnose yourself using the Internet and reference books; be sure to visit a doctor for a detailed study of the situation. Only a doctor can advise you on what additional examinations you should undergo and what medications, if necessary, you should start taking.

How is the indicator survey carried out?

To determine the distribution of red blood cells, the patient is asked to donate a small amount of blood from a vein. Using a special tube, the material is collected and placed in a sealed and sterile container, which is sent to the laboratory. The procedure is not painful; the only consequence may be a small hematoma at the injection site. Most often it appears in people with high hemoglobin or blood sugar. There is no need to worry about this.

To reduce the risk of anemia and other diseases related to the number of red blood cells in the blood, you should:

1. Limit salt intake.
2. Limit the consumption of alcoholic beverages.
3. Start using proper food.
4. Start fighting excess weight.
5. If possible, change the environmental situation around - toxic substances have an adverse effect on health.

In addition, pharmacies sell various herbal remedies that help combat this problem.

They are absolutely safe. Talk to your doctor about which set of herbs is best for you.

The erythrocyte distribution index is decreased or increased: what does this mean?

Red blood cell anisocytosis (RDW) is an index of red blood cell distribution based on magnitude. This parameter evaluates in a blood test the number of red blood cells of various sizes that deviate from the normal value. It is a percentage visualization of red blood cell heterogeneity.

What indicator is considered normal?

In an adult, this figure is normally in the range of 11.5-14.5%.

Microcytes are considered to be red blood cells smaller than 6.7 microns. Macrocytes are larger than 8 microns in size. The study of this indicator is informative in determining the type of anemia. Microcytosis in the analysis indicates the presence of iron deficiency anemia, the development of microspherocytosis, thalassemia, sideroblastic anemia. Macrocytosis is characteristic of deficiency anemia (lack of folic acid) and toxic lesions liver. A general increase in anisocytosis is observed in macrocytic anemia, iron deficiency anemia, bone marrow lesions, myelodysplastic syndrome, and hemolytic anemia.

In newborns, physiological macrocytosis is observed, which lasts up to two months of life. In parallel with the anisocytosis index, it is necessary to study the MCV, which takes into account the size of red blood cells, their average volume, and the hemoglobin content in them.

General rules for preparing for blood tests

To obtain the most reliable results, the analysis must be performed on an empty stomach. The interval between blood sampling and the last meal should be at least twelve hours. Drinking water is allowed.

For three days it is recommended to exclude: alcoholic drinks, smoked foods, fried and fatty foods. A few hours before the test, it is not advisable to smoke or exercise. If possible, you should avoid taking medicines a week before blood sampling (with the exception of monitoring the therapy). Tests are not performed after physiotherapeutic procedures, massage, ultrasound diagnostics, rectal examination and radiography.

Increase and decrease in erythrocyte anisocytosis

Iron deficiency anemia is considered the most common cause of changes in the erythrocyte distribution index.

This is a disease that occurs as a result of iron deficiency and is accompanied by impaired heme synthesis, leading to anemia of varying severity.

This pathology blood is quite common and accounts for about 80% of all anemias. Most often, it occurs in women, children and adolescents.

Classification

1. Juvenile - caused by a violation of iron metabolism due to hormonal imbalance, intensive growth and the formation of the menstrual cycle in girls.
2. The acute posthemorrhagic form is associated with the loss of a large amount of blood in a short period of time.
3. Chronic posthemorrhagic iron deficiency anemia occurs with prolonged blood loss (heavy menstruation, hemorrhoids, frequent nosebleeds, untreated gastric ulcer, Crohn's disease, ulcerative colitis, diverticulitis).

According to the degree of severity, they are divided into mild (Hb within 100-110 g/l), moderate (Hb not less than 80 g/l), severe (Hb below 75 g/l). The risk group for the occurrence of iron deficiency anemia includes: women who breastfeed for more than a year, carrying a fourth or more child, patients with chronic blood loss, donors, vegetarians.

The development of this disease occurs in several stages. Initially, prelatent and latent deficits iron, accompanied by its depletion in organs and tissues. Clinical symptoms appear at the stage of reduction of iron in heme-containing pigments, necessary for the synthesis of hemoglobin.

Clinical picture

The manifesto is non-specific anemic syndrome, manifested by pallor of the skin and mucous membranes, drowsiness, weakness, and decreased performance.

Next comes dystrophic lesions of the nails (delamination of their structure, spoon-shaped shape, slower growth). Patients complain of constant dry mouth, difficulty swallowing dry food, the appearance of perverted taste preferences (the desire to eat chalk, raw meat, soil), and a change in the sense of smell. The most characteristic manifestations are considered to be: the occurrence of jams in the corners of the mouth and smoothing of the relief of the tongue (disappearance of the papillae).

During an objective examination, attention is paid to a yellowish-gray tint of the face, dryness and flaking of the skin, and a bluish tint to the sclera.

Diagnostics

The basis for making a diagnosis is characteristic complaints and clinical symptoms, hypochromic microcytic anemia in the CBC.

The color index and hemoglobin saturation level of erythrocytes are also below normal. Severe anemia is characterized by pronounced anisocytosis (the erythrocyte distribution index shifts towards microcytosis) and the development of poikilocytosis. Bone marrow regenerative parameters are not impaired. There is no decrease in the number of reticulocytes.

Indicative are the ferritin level and transferrin saturation coefficient (reduced).

Assessment of specific parameters

Iron deficiency anemia is characterized by a decrease in the average diameter and volume of erythrocytes and an increase in the average RDW value.

A distinctive feature is a decrease in iron-containing red blood cells (siderocytes).

To carry out differential diagnostics with lead intoxication, basophilic punctuation of erythrocytes (in case of poisoning - rougher) and the level of free basophilic protoporphyrin (increased, more than 9.0 µmol/l in case of lead intoxication) are assessed.

Treatment of iron deficiency conditions

The priority is to eliminate background diseases accompanied by chronic blood loss, as well as normalize nutrition.

Simultaneously with the medicinal elimination of iron deficiency, a diet with an increased amount of dietary iron and vitamin C is prescribed, and the consumption of dairy products is limited.

As drug therapy, divalent forms (Totema, Vi-fer, Aktiferrin, Sorbifer) are most effective. The effectiveness of therapy and the increase in hemoglobin levels are assessed every week. In pregnant women, it is advisable to add folic acid to therapy (even if its levels are normal in a blood test).

It is important to remember that preventive measures to prevent iron deficiency in children must begin in the antenatal period. From the second trimester of pregnancy, all women need to be prescribed a maintenance dosage of iron supplements. In the postnatal period, in children receiving artificial feeding and those born from multiple pregnancies, preventive courses are carried out.

Folate deficiency anemia

Folate deficiency develops in the human body.

The disease most often occurs in children, young and middle-aged people, and pregnant women. Also, the risk group includes patients with celiac enteropathy, Crohn's disease and ulcerative colitis, and intestinal cancer.

Clinical picture

Patients complain of weakness, dyspepsia, aversion to food, pain and burning of the tongue, glossitis.

Objectively assessed: pallor of the skin and subicerial sclera, crimson tongue with a smoothed relief. During auscultation of the heart, arrhythmias, extrasystoles, and systolic murmur at the apex are detected.

Diagnostics

A clinical blood test revealed anemia, macrocytosis and an increase in the erythrocyte distribution index. Folic acid levels are below normal with generally normal iron and vitamin B12 levels.

Serum and erythrocyte folate levels are assessed.

Treatment

In the vast majority of patients, folic acid in a dosage of 1 to 5 mg is sufficient to treat folate deficiency anemia. For intestinal diseases, the dose is increased to 15 mg/day.

The minimum duration of prescribed therapy is one month. The treatment is monitored every two weeks.

The following hemogram indicators are assessed:

• level of red blood cells and hemoglobin;
• red blood cell distribution index;
• increase in the number of reticulocytes.

In the presence of enteropathies, it is necessary to prescribe regular preventive courses of folic acid preparations.

Malignant bowel diseases

Accompanied by severe posthemorrhagic iron deficiency and folate deficiency anemia, with a pronounced increase in the erythrocyte distribution index.

Changes in these indicators in combination with clinical symptoms make it possible to identify the disease in the early stages and increase the patient’s chances of survival and further return to life. full life.

The initial manifestations are nonspecific and are characteristic of all neoplasms: symptoms of general intoxication (weakness, chills, fever, muscle and joint pain, refusal to eat), progressive weight loss is observed. Then dyspeptic disorders (nausea, vomiting), bloating, flatulence, diarrhea are added, and if the rectum is damaged, a false urge to defecate appears. Sometimes patients pay attention to streaks of blood in the stool.

As the tumor grows, the general symptoms change to specific ones, characteristic of intestinal cancer. The amount of blood in the stool increases, and complete staining of the stool is possible. This leads to significant anemia in the patient. There is also frequent alternation of long-term (up to 10 days) constipation and diarrhea, pain during bowel movements, a constant feeling of incomplete evacuation, and possible sensation of a foreign body in the intestine. Characterized by a sharp, fetid odor of feces, a high content of mucus, the appearance of streaks of pus, putrid smell from mouth. In women, a tumor may grow into the vagina, followed by the discharge of pus, mucus and feces.

Diagnostics

Further research includes:

1. Digital examination (informative for damage to the rectum).
2. Irrigoscopy (contrast, X-ray examination of the intestine) and colonoscopy (the gold standard examination for suspected oncological lesions of the intestine, allows you to identify the location and estimate the size of the tumor, and perform a targeted biopsy).
3. Fibercolonoscopy with tumor biopsy.
4. Sigmoidoscopy (visualizes the rectum and sigmoid colon);
5. CT scan, radiography, magnetic resonance imaging organs, ultrasonography, ECG, Echo-CG.
6. In women, a vaginal examination is required (possible overhang of the vaginal vault as a result of tumor pressure).
7. Fecal occult blood test.

A complete blood count for bowel cancer reveals anemia, a decrease in platelet count, leukocytosis and a sharply increased ESR (erythrocyte sedimentation rate).

IN biochemical analysis urea and creatinine levels will be significantly elevated. The haptohemoglobin level is sharply increased, the level of total protein, potassium and sodium ions is decreased.

Treatment prognosis

The choice of therapy and its effectiveness are directly dependent on the stage of the disease, the location of the tumor and the presence of metastases. Survival rate with timely treatment (stage 1) is up to 95%.

Basic treatment methods

The use of isolated chemotherapy and radiation methods Treatment for colon cancer is not effective.

1. At stage 1, excision of the tumor is recommended, and, if necessary, resection of the area of ​​the intestine affected by the tumor. Follow-up with an oncologist.
2. Stage 2 therapy consists of resection, followed by the formation of an anastomosis. Combination of radiation (chemotherapeutic) methods with surgery.
3. At stage 3, combined chemo-radiotherapy is required.
4. Stage 4 treatment is usually not effective. Palliative tumor resection is used in conjunction with combination therapy.

Prevention of intestinal cancer includes quitting smoking, normalizing nutrition (sufficient consumption of food rich in plant fiber, fresh fruits and vegetables), maintaining a healthy weight, active lifestyle, regular preventive examinations.

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What can the width of the distribution of red blood cells tell you?

One of the red blood cell indices is the red blood cell distribution width or RDW. It shows how dispersed these blood components are in size.

On average, red blood cells are the same size. They change with age. But if such a picture is observed in a fairly young person, then possible reason development serves this purpose malignant tumor or anemia.

Red blood cells can change not only in size. The shape also changes. Such cases are often observed. To determine disorders, blood is donated for RDW-CV and RDW-SD.

The condition when a change in red blood cells occurs is called anisocytosis. To make a diagnosis, the doctor sends the patient for a general blood test, during which the blood is tested for RDW.

What kind of research is this?

Blood for such an indicator as the width of the distribution of red blood cells is examined in following cases:

• planned analysis;
• in the diagnosis of various pathologies;
• before surgery;
• if you suspect various types of anemia.

It is the latter that serves as the most common indication for this study.

Modern methods carrying out analysis are able to quickly and efficiently conduct any blood test, including assessing the condition of red blood cells (erythrocytes).

The result will be negative if there are no abnormalities, and positive if the RDW is higher. In this case, the doctor will prescribe a repeat examination, which will explain the reason for the increase. The diagnosis cannot be considered accurate based on just one blood sample. For example, after surgery this indicator usually has an increased value. Therefore, in any case, a repeat blood test is required.

Blood for analysis is taken from a vein in an adult, and from a finger in small children. Before collection, you should not eat food 8 hours or less.

The norm for this indicator for an adult is from 11.5 to 14.5% for any age. For infants up to six months - from 14.9 to 18.7%, for other children - from 11.6 to 14.8%. If indicators deviate from these, it is necessary to undergo a comprehensive examination.

When deciphering a blood test, the doctor must also take into account the MCV indicator - the average volume of red blood cells. This is necessary for accurate diagnosis of various anemias. If the distribution width of red blood cells is normal and their average volume is reduced, the following ailments are suspected:

• thalassemia;
• hemorrhage;
• splenectomy;
• malignant neoplasms.

If MCV is low, and RDW, on the contrary, is high, then we can assume beta thalassemia, iron deficiency anemia. And liver disease can be suspected if MCV levels are high and RDW is normal. With both high levels, hemolytic anemia and vitamin B deficiency are possible.

The patient should not be upset if the indicators differ from the norm. The disease that may be detected may not be so terrible. In any case, after clarification of the diagnosis, professional treatment will follow.

If the width of the red blood cell distribution is different from normal

With an increased value of this indicator, red blood cells vary greatly in size. The large size of red blood cells reduces their lifespan. The decrease in the total number of red blood cells depends on this.

If significant destruction of red cells occurs, then excessive formation of iron begins in the blood. And at the same time, bilirubin is formed, which goes to the liver for processing, which does not have the best effect on its load. Because of this, the liver cannot process iron. And this already has an adverse effect on human health in general.

In addition, if the relative width of the distribution of red blood cells is increased, then the spleen enlarges, because this organ serves to remove non-working red blood cells from the body, and produces new ones and releases them into the bloodstream.

Everything in the body is interconnected. This increased efficiency of the spleen also affects the functioning of nearby organs. For example, when increased in size, it puts pressure on the stomach and intestines. It happens that the lungs also experience pressure from the spleen. In this case, the development of respiratory tract diseases may begin.

If RDW is elevated, then the very first suspected disease is iron deficiency anemia.

The different stages of this disease show and different level width of distribution of erythrocytes. At the beginning of the disease it is closer to normal, and then it increases. On the contrary, hemoglobin decreases. Treatment consists of increasing it. Various medications with sufficient iron content are used.

When RDW increases, a person experiences following symptoms:

• yellowness of the skin (due to negative impact to the liver and spleen);
• temperature increase;
• sweating;
• fatigue;
• nervousness.

But since changes in the volume of red blood cells affect many organs, this is far from full list what a person with a blood disorder may experience.

The human body is a complex system. Therefore, the pathology of one organ can cause a malfunction in another. Likewise, disturbances in the width of the distribution of red blood cells cause various diseases.

If RDW is below normal, then it is necessary to retake the test, because this indicator may be elevated or normal.

Any index can be increased or decreased regardless of the presence of disease in the body. The width of the erythrocyte population distribution is no exception.

The patient must meet certain conditions before blood collection. No special preparation is required for the procedure. It is necessary not to eat for 8 hours before the test, and a day or two before this you should not take spicy, salty, pickled or smoked foods. Taking medications is also not recommended. If this cannot be avoided, then you need to warn the doctor about what medications you are taking.

Blood is drawn from both a vein and a finger. But venous blood provides clearer information. If for some reason you have to take tests again, you must do this at the same time as during the initial blood collection.

The patient's blood begins to be processed immediately. Modern medicine uses automatic analyzers, so the results will be ready within 2 days.

The results of the analysis may be affected by the following factors:

• heavy physical activity on the eve of blood sampling and the day before;
• mental work associated with significant concentration;
• radiation exposure during fluoroscopy;
• physiotherapy performed shortly before donating blood.

This applies not only to this analysis. Taking blood for other indicators requires the same preparation, for example, the width of platelet distribution by volume.

It is not considered a significant deviation from the norm if the difference is 1-2%. This can be observed when taking blood from a baby (his circulatory system has not yet fully matured), after various injuries, during the premenstrual period in a woman (or immediately after). Therefore, deciphering only one analysis for an experienced doctor will not serve as a reason to diagnose the disease. He will definitely appoint a second one.

Width of distribution of erythrocytes by volume

The most accessible and highly effective diagnostic method in modern medicine is a clinical blood test. Such a study is prescribed in almost all cases when a person seeks medical help for various ailments. Any changes in the blood composition allow a specialist to suspect the development of various diseases at an early stage of their development. In addition, with the help of analysis, it is possible to identify the causes of the appearance of one or another symptom. During a blood test, the laboratory evaluates the parameters of absolutely all blood elements, of which there are more than 20 today. Among them is an important RDW indicator in a blood test - the erythrocyte index. The abbreviation stands for “width of distribution of red blood cells by volume.”

RDW indicator in blood test

Erythrocytes are red blood cells that give blood its red tint. These cells provide the organs and tissues of the body with oxygen. In people in good health, these cells do not differ in shape, color or volume. It is important to know that the proper functioning of blood cells does not depend on their size, but on their volume. With age, however, red blood cells decrease slightly in volume, causing differences to form between cells. Differences may also appear in certain pathological processes or in anemia. If different red blood cells are found in the human body, then experts call this condition “erythrocyte anisocytosis.”

Red blood cell anisocytosis and its extent are examined by RDW analysis, which shows the degree of heterogeneity of red blood cells in size.

So, if the width of the distribution of red blood cells exceeds normal values, then this condition indicates that the size of the red blood cells is greatly increased, and their life cycle is reduced. In this condition, the normal content of red blood cells in a person’s blood is disrupted. If RDW-cv is lowered, then there is reason to suspect the patient has a condition in which blood formation occurs more slowly than expected, namely any degree of anemia (anemia).

The RDW-cv index shows the difference in red blood cell volume from the average.

The RDW-sd index indicates how much cells vary in volume (relative distribution width).

Analysis

The analysis for RDW-cv is carried out during a clinical (general) blood test. As a rule, such an analysis is prescribed upon admission to inpatient treatment, when visiting a general practitioner, as well as when diagnosing various diseases.

Such research plays the most important role in preparing the patient for any kind of surgical intervention.

Preparing for analysis

In order for the analysis to show truly correct results, before donating blood you need to follow some rules:

• blood is donated only in the morning;
• Before donating blood, the patient is prohibited from consuming any food or liquids (except for still mineral water);
• 24 hours before the analysis, it is necessary to limit physical and emotional stress;
• If you are taking any medications, notify your specialist in advance.

What can affect the result?

IN Lately blood is examined using a special medical equipment, which has proven itself to be very good. However, it is rare for this kind of “machines” to malfunction. Therefore, there is always a risk of error in the correctness of the study. The best and most reliable method of analysis is to count blood elements and decipher the indicators manually. But, in view of the fact that this method is labor-intensive and has long been abandoned in most laboratories.

If the result of the RDW-cv analysis is not normal, a repeat study is usually prescribed.

Distortion of the analysis results on the width of the distribution of red blood cells by volume can be affected by non-compliance with the rules of preparation for blood sampling.

So, for example, if a patient, especially a child, was nervous or physically active before donating blood, then there is a possibility of inaccuracy in the indicators.

How is it carried out?

To study RDW in a blood test (cv and sd), biomaterial is taken from a vein. In patients childhood If it is impossible to take blood from a vein, take capillary blood - from a finger. The blood sampling procedure is relatively painless, however, after the procedure, some people note the formation of a small hematoma at the site where the skin was punctured with a needle. This manifestation may indicate an increase in hemoglobin or sugar levels.

Norm

The normal indicators for both men and women vary between 11-15%.

If the width of the distribution of red blood cells deviates in any direction by at least 1%, then such a deviation is considered pathological.

In patients younger age The norm for the indicator “width of distribution of red blood cells by volume” varies depending on age:

• 0-6 months - 15-19%;
• 6 months-3 years - 12-15%;
• over 3 years old - 11-15%.

Deciphering of analysis data is carried out only by an experienced specialist.

Increased values

Enlarged cells have a lower life cycle, which negatively affects the overall number of these blood cells.

With significant destruction of red blood cells in the body, the formation of large amounts of iron and bilirubin begins. The latter enters the liver for processing, and its large volume leads to a significant load on the hematopoietic system.

In addition, an increase in RDW-cv/sd sometimes leads to an increase in the size of the spleen, as well as to a load on neighboring internal organs(an enlarged spleen puts pressure on the organs of the digestive system).

The RDW-cv norm is usually exceeded for several reasons, including:

• chronic pathologies liver;
• vitamin B12 deficiency;
• oncological diseases, malignant neoplasms.

Among the causes that are not pathological, there are:

• alcoholism;
• overconsumption salt;
• obesity;
• intoxication.

Reduced values

A decrease in the RDW-cv/sd norm is very rare.

If the decoding of the blood test showed that the width of the distribution of red blood cells is lower than the established norm, the patient must definitely donate blood again. If a repeated test indicates a decrease in RDW, the attending physician must determine for what reason this condition arose:

• extensive blood loss;
• iron deficiency in the patient's body;
• avitaminosis;
• destruction of red blood cells;
• leukemia, myeloma;
• malignant neoplasms;
• hemolysis.

In order to maintain normal health, every person must lead healthy image life and listen to your body. For any sign feeling unwell you should consult a doctor.

It is important to remember that timely detection of any disease increases the chances of a speedy recovery.

Red cell distribution width (RDW, from red cells distribution width) is an erythrocyte index that allows you to determine the heterogeneity of cellular volume in peripheral blood.

The appearance of red blood cells of different volumes in the blood is called anisocytosis, the degree of which allows one to determine the RDW index.

Red blood cells, their functions in the body, main indicators

Erythrocytes, or red blood cells (RBC, red blood cells), are red blood cells, biconcave disc-shaped blood cells, devoid of a nucleus. The shape of a red blood cell allows the cell to deform as it moves through blood vessels small caliber. The main function of red blood cells is to transport oxygen from the lungs to tissues and organs, and from them - carbon dioxide to the lungs. Red blood cells are formed in the bone marrow and destroyed in the spleen; the average lifespan of cells is 120 days. Newborns have larger red blood cells than adults.

A physiological increase in the number of red blood cells is observed in children in the first days of life, with frequent stress, intense physical activity, malnutrition or fasting, and with prolonged clamping of a limb with a tourniquet during blood collection for a blood test. A physiological decrease in the number of red blood cells occurs immediately after eating, between 17:00 and 07:00 and when blood is drawn from the patient in the supine position.

In the blood, in addition to normal red blood cells, there may be cells that differ in size - larger (macrocytes) or small (microcytes) red blood cells. The condition in which there are more than 50% macrocytes in the blood is called macrocytosis. If 30–50% of microcytes are present, microcytosis is diagnosed. The appearance of red blood cells of different volumes in the blood is called anisocytosis, the degree of which allows one to determine the RDW index.

To erythrocyte indices in general analysis blood, in addition to RDW, include MCV (mean erythrocyte volume), MCH (mean erythrocyte hemoglobin content), MCHC (mean erythrocyte hemoglobin concentration).

Erythrocyte indices are determined during a general (clinical) blood test. The count is carried out using an automatic hematological analyzer, according to the appropriate formulas and/or in a stained blood smear under a microscope when calculating the leukocyte formula. In addition to RDW, erythrocyte indices in a general blood test include MCV (average erythrocyte volume), MCH (average hemoglobin content in an erythrocyte), MCHC (average hemoglobin concentration in a erythrocyte mass).

How to properly prepare and take a general blood test

General blood analysis - basic research which is carried out according to the following indications:

• prevention, with the aim early detection probable pathologies;
• diagnosis of diseases;
• control of therapy;
• before surgical interventions;
• monitoring the progress of pregnancy.

A general blood test includes counting the number of blood cells (erythrocytes, leukocytes, platelets), determining hemoglobin concentration, hematocrit level, erythrocyte and platelet indices, and erythrocyte sedimentation rate. A complete blood test includes a leukocyte count.

For preventive purposes, a general blood test should be taken annually. Persons from risk groups (with a family history, presence of chronic diseases, occupational hazards, during pregnancy, etc.) this study may need to be carried out more frequently - 2 times a year, 1 time every 3 months, and sometimes more often.

Blood for a detailed general analysis, which includes the determination of erythrocyte indices, including the RDW indicator, is usually taken from a vein. In some cases, capillary blood may be collected from a finger. Blood is donated in the morning on an empty stomach, at least eight hours after the last meal. Before donating blood, you should avoid mental and physical stress and stop smoking. It is advisable not to carry out medical procedures the day before.

If the RDW index is low, this often means the need to retake a general blood test.

Decoding RDW in a blood test: the norm in women and men

The RDW-CV indicator (CV - coefficient of variation) displays the relative width of the distribution of red blood cells by volume, i.e. how much the volume of red blood cells differs from the average, and is measured as a percentage. The index is influenced by the MCV indicator, fluctuations of which lead to an increase in RDW-CV. The norm for this indicator for adult men and women is 11–15%. In infants up to 6 months, the RDW-CV rate is 15-19%. In children over 6 months of age, the norm corresponds to that for adults.

When deciphering RDW-SD in a blood test (SD - standard deviation), it is taken into account that this indicator does not depend on the MCV index. This index shows how different the red blood cells in the blood are in volume and size, that is, what is the difference between small and large cells. The normal RDW-SD indicator is 42±5 fl.

The RDW-SD index is more accurate in the case of a small population of micro- or macrocytes, and the DW-CV index more accurately reflects the overall changes in red blood cell volume.

Reasons for deviations from the norm in the RDW indicator in a blood test

An elevated RDW level means that there is heterogeneity, i.e., dissimilarity in the volume of the red blood cell population, and may also mean the presence of several populations of red blood cells in the blood (for example, after a blood transfusion).

If in a blood test RDW-CV is increased by 15% or more, this indicates the presence of red blood cells of different volumes in the blood; the higher this index, the greater the difference in the volume of red blood cells. A falsely elevated RDW-CV result may be due to the presence of cold agglutinins in the patient's blood sample - antibodies that cause aggregation, i.e. sticking together of red blood cells when exposed to low temperatures.

Blood for a detailed general analysis, which includes the determination of erythrocyte indices, including the RDW indicator, is usually taken from a vein.

An increase in RDW is observed in the following pathologies:

• microcytic anemias;
• lack of iron, vitamin B 12 and/or folic acid in the body;

When deciphering a general blood test in general and the RDW indicator in particular, the values ​​of the erythrocyte MCV index are taken into account:

• normal RDW + reduced MCV– after blood transfusion, post-traumatic splenectomy, chemotherapy, hemorrhages, thalassemia, oncological diseases;
• decreased MCV + increased RDW in blood test– iron deficiency, red blood cell fragmentation, beta thalassemia;
• elevated MCV + normal RDW– for liver diseases;
• increased MCV + increased RDW– with hemolytic anemia, vitamin B12 deficiency, the presence of cold agglutinins in the blood sample, as well as during chemotherapy.

Elevated RDW blood test values ​​may also be obtained immediately after surgery or blood transfusion.

If an RDW result is obtained that is outside the reference values, additional research is required.

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If the RDW blood index (red blood cell distribution width) is higher than normal, this means that the risk of anemia is increased and a person with such blood values ​​should visit a hematologist as soon as possible. Elevated RDW values ​​indicate, in addition to anemia, also an increased risk of malignant blood pathologies caused by bone marrow diseases.

Determination of the distribution width of red blood cells

The RDW value shows the heterogeneity (diversity) of red blood cells (Er) in size. Normally, the average erythrocyte volume (MCV) in an adult is from 80 fL to 95-100 fL (µm 3). The appearance of small erythrocytes (microcytes) and/or large Er (macrocytes) is noted in blood pathologies.

Various types of anemia and myeloproliferative diseases are accompanied by changes in the size of red blood cells. Transformed ones appear in the blood Er, the sizes of which are smaller or larger than normal.

The range of Er size values ​​from the smallest microcytes to the largest macrocytes is called the width of the erythrocyte volume distribution.

The following erythrocyte indices have clinical significance and are necessary for diagnosing anemia and bone marrow pathologies:

• RDW-CV is the coefficient of variation (CV) of Er dimensions;
• RDW-SD - means the relative width of the distribution of red blood cells by volume.

What the RDW-CV shows

The RDW-CV index is measured as a percentage and is calculated based on the Er distribution width graph. The coefficient of variation is calculated in the following way:

RDW-CV = SD*100%/MCV.

The calculated distribution of the width of erythrocytes KB depends on the average size of erythrocytes, ifRDW-CV is increased, this may mean an increase in the number of macrocytes and an increase in microcytes.

The SD value is the deviation of the Er value from the average value to the greater and lesser sides from the midline on the graph.

Changes in this index can be monitored using the erythrocyte histogram.

• As the coefficient of variation increases, the shift of the histogram to the right increases when a significant number of macrocytes appear.
• The predominant content of microcytes leads to a shift of the histogram to the left, towards smaller values ​​of erythrocyte cells.

RDW-SD Index

The hematology analyzer calculates the RDW-SD indicator automatically and produces a ready-made result based on the red blood cell histogram. This blood index is measured in fl (µm 3), and means the difference between the largest and smallest Er.

And ifRDW-The CV hematology analyzer calculates using the formula, then to calculateRDW-SD requires red blood cells (RBC) histogram. On it, along the OX axis, the quantities are indicatedEr, measured in fl, on the OY axis is the total number of red blood cells in percent.

The RDW-SD value is numerically equal to the length of the straight line segment on the OX axis drawn on the erythrocyte histogram at the 20% level along the OY axis.

RDW standards

Normally, the relative spread width Er RDW-SD is constant and amounts to 37 – 47 fl. A pathological deviation in the size of erythrocytes from the norm or anisocytosis is noted when RDW-SD values ​​are more than 60 fL.

On the histogram, this means that the value of the relative width of the volume distribution is increased if the spread of erythrocytes in the sizes of the smallest and largest Er on a straight line drawn along the OY axis at the level of 20% is greater than 60 fl.

Norms for the coefficient of variation of erythrocytes RDW-CV - volume distribution width, table.

The normal distribution width of erythrocyte cells changes during pregnancy and is by trimester:

• in the first – 11.7 – 14.9%;
• in the second – 12.3 – 14.7%;
• in the third – 11.4 – 16.6%.

The RDW-SD indicator is characterized by increased sensitivity to the appearance of microcytes. RDW-CV exhibits particular sensitivity to anisocytosis, the occurrence of deviations in the size of Er blood.

The level of anisocytosis of a blood sample reflects the heterogeneity (variability) of red blood cells in size.

There are different degrees of anisocytosis:

1. The first – 30 – 50% Er deviate in size from the norm.
2. The second – 50 – 70% of transformed cells.
3. Third – more than 70% of Er deviate from the standard.

Analysis transcript

Red blood cell RDW indices obtained when processing a sample with hematological automatic analyzers are necessary for early diagnosis:

• deficiency of Fe, folate, vitamin B12;
• types of anemia;
• morphology of erythrocytes - structural features and sizes;
• myeloproliferative diseases affecting the bone marrow.

Decoding of the analysis data is carried out taking into account all erythrocyte indices. When interpreting the distribution width Er, the MCV value is of particular importance.

Raising RDW

The index of distribution of erythrocytes by volume is increased in anemia caused by B12 deficiency, and this means that the number of macroerythrocytes in the blood is increased, and the histogram is shifted to the right.

If the volume distribution width is increased, but the erythrocyte index such as MCV is increased, we can assume:

• hemolytic anemia;
• B12 deficiency;
• cold agglutination is a disease associated with the appearance in the blood of antibodies that glue red blood cells to each other in response to the action of cold.

Increased RDW (wide distribution of erythrocytes) and increased MCV in liver diseases, anemia caused by lack of vitamin B9.

An increase in the distribution width with a reduced index of average erythrocyte volume is observed in diseases:

• thalassemia;
• iron deficiency.

An increase in the Er spread width with normal MCV values ​​may indicate:

• for a lack of vitamins B9 and B12;
• on the development of iron deficiency.

With increased values ​​of the distribution width in the blood, accelerated destruction of red blood cells occurs, which is why the liver and spleen work at the limit of their capabilities. This leads to disruption of their functions, which manifests itself:

• the appearance of excess bilirubin;
• high Fe content;
• enlarged spleen.

Lower RDW

A decrease in the volume distribution width of Er means that there are cells of similar sizes in the blood. The boundaries of the spread of the RDW-CV value are narrowed in the following cases:

• oncological diseases - myeloma, leukemia;
• hemolysis - destruction of red blood cells;
• injuries with significant blood loss;
• deficiency of iron, B vitamins.

When decreasingRDW- CVs up to 10.2% suggest macrocytic or microcytic anemia. In these forms of the disease, red blood cells are predominantly increased or decreased in size compared to the norm.

Microcytic anemias include iron deficiency, iron saturation, and iron redistribution. Macrocytic anemia develops with hypothyroidism, pregnancy, liver disease, hematopoietic disorders in the bone marrow, lack of copper, vitamins B12, and folic acid.

A blood test can determine not only the quantitative, but also the qualitative composition of the blood. The size, shape, color and volume of cells are additional criteria for diagnosing diseases. Sometimes in a general analysis, in addition to red, white, flat cells, RDW is indicated, which means the distribution of red blood cells in width.

What is RDW in blood test?

The color of our blood is given by red cells - red blood cells. They are shaped like a disk, concave in the middle on both sides. They are produced by red bone marrow. The composition of the cells contains hemoglobin - this is a protein that takes part in metabolism. It binds oxygen in the lungs, then delivers it to the tissues.

Normally, all red blood cells have the same size, shape, and color, so that if necessary, one cell can replace another and perform the same functions. At various diseases some red blood cells increase in size. Large cells cannot pass into the narrow lumen of the capillaries, blood circulation is disrupted, so the body utilizes unnecessary elements.

RDW is an index that shows the ratio of healthy and enlarged red blood cells by diameter. 2 RDW indicators are determined:

• RDW CV – distribution of erythrocytes by value in percentage;
• RDW SD - determines the difference between the smallest and largest red blood cells.

Red cells of medium size and volume are taken as the RDW standard: normocytes with a diameter of 7-7.5 microns. The indicator is measured in femtoliters - this is the proportion of volume relative to a liter.

Analysis on RDW

An RDW test shows anisocytosis of red blood cells, that is, the presence of red cells of irregular size. In addition to normocytes, in anisocytosis there are:

• Microcytes – their diameter is less than 7 microns;
• Macrocytes – diameter from 8 to 12 microns;
• Megalocytes – more than 12 microns.

When red blood cells differ greatly in size from normal blood cells, anisocytosis is diagnosed. Depending on which cells predominate, microcytosis, macrocytosis and a mixed state occur.

RDW is determined in a general clinical analysis, which is carried out routinely, during diagnosis or before surgery.

The value of the indicator needs to be known if anemia is suspected, differential diagnosis various types diseases, as well as to monitor the quality of treatment.

Blood is taken from a finger in the morning on an empty stomach. The laboratory calculates the degree of decrease or increase in RDW. A laboratory technician can do this manually or using a modern hematology analyzer. The device shows more accurate values, the result is determined faster.

When the level of anisocytosis is elevated, it is necessary to retake the blood for histogram analysis, since the width of the distribution of red blood cells changes frequently and quickly.

Normal RDW in blood test

The normal RDW value is independent of age and sex differences in adults. In newborns and older children, this figure may normally be slightly increased compared to adults.

RDW rate table in percentage:

There are several degrees of anisocytosis:

• I degree – slight increase, large and small red blood cells are in the range of 30-50%;
• II degree – moderate increase: from 50% to 70%;
• III degree – marked increase in anisocytosis: more than 70%;
• IV degree - almost all red blood cells are changed.

Analyzers count the number of red cells different sizes per 1 μl of blood, as well as deviation in size by degree. In addition to RDW - the distribution width of red blood cells by diameter - a study is used on MCV - the distribution of red cells by volume. Knowledge of the second indicator is necessary for more accurate diagnosis.

Increased RDW values

An increase in the RDW index from the normal value indicates that diseases are present in the body. If the width of the distribution of red blood cells is increased, this means that most of the red cells have become deformed and modified. The lifespan of such cells is reduced, this affects the total number of red blood cells in the body: the indicator decreases.

RDW is elevated in blood tests in the following diseases:

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A change in the diameter distribution of red cells may also indicate cardiovascular pathology and the development of cardiac ischemia.

With high quality and timely treatment the erythrocyte distribution index increases as many young erythrocytes of normal diameter appear.

RDW in blood test is reduced

A decrease in the width of the distribution of erythrocytes below normal practically does not occur. With some types of anemia, it may remain within normal values:

• Aplastic anemia – bone marrow stem cells are affected, causing blood cells to not mature and grow;
• Posthemorrhagic anemia – after bleeding;
• Anemia in chronic diseases;
• Spherocytosis - red cells take on the shape of a ball and are quickly destroyed (a type of hemolytic anemia);
• Thalassemia is a hereditary disease in which red blood cells are deformed and is dangerous due to the development of a hemolytic crisis;
• Sickle cell anemia is a genetic blood disease, a cell defect does not allow hemoglobin to bind in full, the cells elongate in shape and resemble a sickle, which can lead to blockage of blood vessels throughout the body.

Since there are a great many different types of anemia, in medicine RDW index plays vital role for diagnosing diseases. The indicator is also determined to monitor the effectiveness of treatment in order to, if necessary, make changes to treatment measures without causing complications and serious consequences.