What does an increase and decrease in RDW mean in a blood test? An increase or decrease in the erythrocyte distribution index - what does it mean.

There are certain types of diseases that are detected in the early stages using an RDW blood test. Because the presence of various pathologies (or absence thereof) is influenced not only by the number and volume of red blood cells, but also by the presence of red cells in the blood, whose volume significantly exceeds the average.

What it is

Red blood cells are the basis of blood. They are red cells. They are the ones that color the blood red. Red blood cells provide oxygen to all human tissues and organs. A healthy person’s blood contains red blood cells that are the same in size, shape and color.

Their correct operation is greatly influenced by the volume of red blood cells, but not the diameter. The average volume of red blood cells is characterized by the MCV parameter. In a healthy person, this indicator is within small limits. Such fluctuations (that is, the range from the smallest erythrocyte volume to the largest) in medical terminology are usually called the width of the erythrocyte distribution or the heterogeneity of erythrocytes. The diagnostic that establishes this characteristic is called RDW.

As you know, in the blood of a healthy person there are red cells of various sizes. Medical experts call this phenomenon anisocytosis. Its parameter is the main indicator (index) of blood cells. This index is usually denoted RDW - this is an abbreviation for the English name red cell distribution width. The RDW parameter is calculated based on the standard deviation of the red blood cell volume from the MCV. Anisocytosis is also detected when examining a blood smear, but obtaining results takes longer than when identifying RDW in a blood test. Basically, such a blood test is carried out on hematological equipment, while modern technologies make it possible to diagnose a blood sample using several parameters simultaneously. A modern analyzer establishes the average volume of red blood cells, as well as the degree of deviation from the norm of this parameter.

General blood test and decoding of RDW indicator

The RDW indicator is studied during general (clinical) blood diagnostics. Such an analysis can be prescribed both routinely and to identify many types of diseases. Patients also undergo a general blood test before surgery. And a repeated clinical blood test can be prescribed for those people who are undergoing therapy for anemia.

When analyzing blood, the RDW indicator is used in conjunction with the MCV indicator. This combination helps to determine, during a differentiated assessment of characteristics, one or another type of microcytic anemia. With a low MCV, a normal RDW may be observed, which is an important indication of symptoms of diseases such as thalassemia, blood transfusion, hemorrhage, post-traumatic splenectomy. In addition, such RDW indices can occur in malignant neoplasms and chemotherapy. If, with the same low MCV, an increased RDW is observed, this may indicate the presence of iron deficiency, beta thalassemia or red blood cell fragmentation.

A situation may also occur when the MCV characteristic is overestimated, and the RDW blood parameter is normal. This combination indicates liver disease. And with elevated MCV and RDW parameters, a blood test indicates the presence of diseases such as B12 deficiency anemia, cold agglutination and hemolytic anemia. In addition, these characteristics of red blood cells are also encountered during chemotherapy.

Heterogeneity of erythrocyte parameters is normal

The use of hematological analyzers in modern medicine contributes to the rapid and high-quality study of the entire human circulatory system. They help to assess the state of red cells in a person’s blood during the treatment period, as well as establish directions for further therapy. But all analyzers are based on the blood test method.

Heterogeneity of erythrocytes is the appearance in the blood of red cells of different volumes. But their predominant number indicates certain diseases. It is generally accepted that the RDW rate in the blood should not exceed 11.5-14.5%.

When characterizing the erythrocyte RDW index, it should be taken into account that this parameter does not depend on the average size of the erythrocyte. Therefore, in some cases, deviations from the norm RDW in the blood may not appear. This is due to the fact that a large number of red blood cells of an already modified type are present in the blood. They are often called macrocytes. And their appearance in the blood gives false positive results during diagnosis. Reliable data in such cases can be obtained by studying the Price-Jones curve.

During differentiated diagnosis of anemia, the RDW norm in a blood test is determined by the MCV indicator, the characteristics of which must also be normal (that is, the MCV indicator is normal, RDW is also normal).

Increasing the indicator

The RDW indicator is elevated in the blood test in several cases. First of all, an increase in this indicator is the main sign of iron deficiency anemia. But elevated characteristics may also indicate chronic liver disease, folate or vitamin B12 deficiency.

Iron-deficiency anemia is the most common type of anemia. And at different stages of disease development, the RDW indicator is increased unequally. This is clearly visible on the erythrocyte histogram. It is known that in the initial stage of iron deficiency anemia, red blood cells are within normal limits, but the amount of hemoglobin will be at the lower limit of normal (or reduced). Such characteristics indicate normal activity of human bone marrow.

In the second stage of iron deficiency anemia, the red blood cell histogram begins to expand to the left (that is, increase), and the RDW increases. Disturbances in hemoglobin formation cause a decrease in parameters such as MCV (average erythrocyte volume), MCH (average hemoglobin content in an erythrocyte), MCHC (average hemoglobin concentration in an erythrocyte), but anisocytosis of erythrocytes will always be increased. And such changes are clearly visible on the histogram. It will noticeably increase to the left. When treating anemia of this type, the level of hemoglobin content and its main characteristics in the blood is normalized. This is achieved by taking iron supplements.

The RDW index is directly related to anisocytosis. The arrangement of red blood cells in size in a blood test acts as an indicator of the level of this complex chemical process, that is, the heterogeneity of red blood cells in diameter. This test detects the presence of red blood cells that are larger than the standard size.

There are different reasons why rdw may be elevated in a blood test. To better understand this issue, a complete understanding of what RDW is is necessary.

Definition of RDW

The basis of blood is made up of red blood cells of a disc-shaped, biconvex shape, that is, erythrocytes. They are entrusted with a vital mission, to deliver oxygen to the systems, organs and tissues of the human body. And transport the spent carbon dioxide back to the lungs for disposal. The concept of erythrocyte heterogeneity determines the range of fluctuations in the volume of red blood cells or the width of their distribution over the volume.

There are two types of RDW indicator:
rdw cv is the relative width of the distribution of erythrocytes by volume, which demonstrates the coefficient of heterogeneity of erythrocyte sizes. The rdw cv indicator in a blood test is necessary to determine how different blood cells are from each other.

rdw sd - identifies the standard deviation from the norm of red blood cells, the data detects differences in the distance between the minimum and maximum volume of red blood cells.

In a healthy body, red blood cells have a uniform color, volume and shape. When the width of the distribution of red blood cells is increased, this is a clear sign of the onset of pathology. The correct functioning of red blood cells is also indicated by a normal MCV indicator, indicating the average volume of red blood cells or their difference within insignificant, acceptable limits. The MCV coefficient is only relevant for a complete determination of the RDW CV readings. If MCV levels decrease, RDW may increase, indicating the presence of one of the abnormalities, such as anemia, anisotropy, or thalassemia.

The most common source of the problem of blood cell transformation is an unbalanced diet. If the change in blood quality is not critical, then most likely the issue is a lack of certain microelements, primarily such as A, B9, B12, as well as iron and folic acid. When the cause is poor nutrition, it is often enough to correct the situation by consuming foods rich in essential nutrients.

If the indicator is significantly higher than normal, then there is reason for concern and a thorough examination.

More serious culprits for changes in red blood cell volume include the following reasons:

Drinking low-quality, untreated or chlorinated water.
Disturbance of the respiratory or cardiovascular system.
Growing up and approaching old age.
Genetic predisposition.
Development of iron deficiency anemia.
Complications after colds, flu, ARVI.
Chronic infections.
The appearance of certain diseases (malignant tumors, oncology and other pathologies).

The process of changing the volume of red blood cells is called anisocytosis. To obtain an indicator of erythrocyte anisocytosis, it is necessary to draw blood from a vein or finger and conduct a laboratory test for RDV. Thanks to modern analyzer devices, it is possible to quickly and with a high percentage of reliability examine blood.

Degrees of anisocytosis

Erythrocyte anisocytosis is divided into four stages:

I degree. Diagnosed when 27% or 50% of red blood cells have a different volume.
II degree. Occurs when 55% or 70% of red blood cells have a change in size.
III degree. More than 75% of blood cells are modified and have different dimensions.
IV degree. Almost 100% of blood cells are different from normal.

Clinical analysis reveals blood levels of rdw, ranging from a slight degree to a pronounced degree, when the highest percentage of deviation from the blood flow composition standards is detected. In ideal condition, the size of red blood cells should vary between 7-9 micrometers. According to the degree of change in the size of red blood cells in one direction or another, anisocytosis is classified into:

Macroanacitosis - a larger number of red blood cells of increased volume.
Microanacitosis is the predominant number of red blood cells of small diameter.
Mixed type, combining macrocytes and microcytes.

There are also megalocytes, which have the maximum possible blood cell size of more than 12 microns. Macrocytes are red blood cells whose size is more than 8 microns. Their normal amount should be in the range of 12−15%. Microcytes include blood cells smaller than 6.9 microns. Mixed anisocytosis is characterized by the presence of both reduced and enlarged blood cells in the bloodstream. Combined studies are carried out using the calculation method using the Price-Jones curve.

Symptoms of increased RDW

In a situation where deviations in the functioning of the circulatory system exceed a minor degree, the body begins to send alarm signals in various ways.

It is always easier to eliminate nutritional deficiencies or begin treatment of a disease at an early stage than to bring the situation to a critical limit.

The following signs may indicate that rdw is elevated:

Strong and systematic increase in temperature.
Profuse sweating.
General fatigue, loss of activity, drowsiness.
A sharp, without a fundamental change in mood.
Occasionally, yellowing of the skin occurs.

If you notice the above symptoms, you should not self-medicate or hope that it will “go away on its own.” After all, taking a general blood test at a clinic or the nearest laboratory and asking a therapist for a transcript will not be difficult. Especially in comparison with the possible consequences if anisocytosis is allowed to develop to degrees II, III, IV.

It is important to understand that the importance of blood testing is very great. When rdw in a blood test is elevated, only a qualified doctor will be able to make the correct diagnosis based on the data obtained. In addition, adding to them possible additional symptoms that may worry the patient. And, as you know, the disease is easier to prevent or eliminate at the initial stage.

In contact with

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 the total number of red blood cells 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 the distribution of erythrocytes can be various kinds of chronic liver diseases, lack of vitamin B12, various types of neoplasms, cancer and other diseases.

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 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 fatigue are manifested. On the part of the human nervous system, 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 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 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 erythrocyte volume distribution is not increased, and 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:

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 of erythrocytes (poikilocytosis);
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;
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 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 the necessary research in laboratory conditions to identify pathologies in the collected plasma and its constituent cellular elements in the form of erythrocytes, leukocytes and platelets. The described elements to perform their normal function are determined 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 of the 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 the RDW level is high. 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) is an indicator that determines the standard type of deviation from the norm, 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 caused by the deformation of the human skull, 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 help from doctors and, for your own safety, conduct a complete examination of the entire body. Only in this way can you protect yourself, thereby preventing one or another possible already emerging disease.

Red blood cell distribution width (RDW) norm (table). Red blood cell distribution width (RDW) is increased or decreased - what does this mean?

Red blood cell distribution width or RDW, as this indicator is usually indicated in tests, allows you to estimate not only the number of red blood cells in the blood, but also the range of their distribution, as well as their size. From the biggest to the smallest and how different they are from each other. As a rule, identical blood cells are approximately equal in volume. And red blood cells are no exception. However, some pathologies upset this balance, and a discrepancy may appear between them, sometimes quite significant. Using the red blood cell distribution width index, or RDW, some diseases can be detected at their earliest stages, when there are no other signs yet.

Erythrocytes are red blood cells, which are the basis of blood. They contain hemoglobin, which transports oxygen throughout the body, maintain the acid-base balance of the blood, remove carbon dioxide from cells and perform other important functions. That is why special attention is paid to red blood cells when analyzing blood - they are studied and compared using several different indices. In particular, the width of the distribution of red blood cells is measured using a special hematological device that captures the impulses that red blood cells transmit. The stronger these impulses, the larger the red blood cells and vice versa. The measurement result is recorded as a percentage or in femtoliters - fl.

Red blood cell distribution width (RDW) is normal. Explanation of the result (table)

The test for the width of distribution of red blood cells is a mandatory component of a clinical blood test. This index is necessary in order to correctly interpret the results of the study and be able to diagnose anemia in a timely manner, while simultaneously differentiating between them. The distribution width of erythrocytes - RDW - is necessarily compared with their average volume - MCV, since it can often be within the established norm, while the erythrocytes themselves turn out to be too large or, conversely, too small, which in itself indicates the presence of pathology .

Blood is taken from a vein in adults and from a finger in children. In some cases, a hematological smear is used, but this test often produces incorrect results.

Red blood cell distribution width (RDW) is the norm for ordinary people and pregnant women:

If the red blood cell distribution width (RDW) is increased - what does it mean?

If the width of the distribution of red blood cells exceeds 14.5%, this indicates that the sizes of red blood cells differ significantly from each other. There may be several options here. First of all, as already mentioned, it is also necessary to estimate the average volume of erythrocytes MCV, that is, the size of the average space occupied by each individual erythrocyte. If this indicator is also too high, then this may indicate the following pathologies:

liver diseases – this organ is responsible for removing harmful toxins from the body, at the same time it synthesizes important chemical compounds and performs various other functions,
hemolytic anemia is a pathological condition in which red blood cells are destroyed much earlier than their normal lifespan,
deficiency of vitamin B12 or folic acid.

If the RDW index is increased and the MCV index is decreased, then the reasons for this phenomenon may be the following:

iron deficiency anemia – due to iron deficiency, the body produces insufficient hemoglobin,
Thalassemia is a blood disease in which the synthesis of elements necessary for the production of hemoglobin is disrupted. In this case, the red blood cells fragment (break down into smaller parts), which leads to a decrease in their average size, while the width of the red blood cell distribution remains high.

If the RDW index is elevated, but the MCV remains within the normal range, then this may indicate a deficiency of folic acid or vitamin B12. Or – about the initial stage of iron deficiency anemia.

An increased level of erythrocyte distribution width indicates that the lifespan of erythrocytes is shortened, they are destroyed, and excess bilirubin and iron are released into the blood. This overloads the liver and prevents it from performing its basic functions, and also leads to an enlargement of the spleen, which has to work in emergency mode to utilize the remnants of destroyed red blood cells. This often leads to damage to the organs closest to it - the intestines and stomach. Due to problems with the liver and spleen, patients with increased levels of red blood cell distribution often have an unhealthy yellowish skin tone.

If the red blood cell distribution width (RDW) is reduced - what does this mean?

If the red blood cell distribution width (RDW) is below 10.2%, this indicates that the red blood cells do not differ significantly in size from each other. Here are two main reasons for this phenomenon:

macrocytic anemia is a blood disease in which there is a deficiency of red blood cells. They are synthesized, but their sizes are too large,
Microcytosis anemia is a blood disorder in which only abnormally small red blood cells are produced.

In both cases, red blood cells are almost the same size, which leads to low RDW values.

Other reasons why the distribution width of red blood cells decreases:

oncological diseases,
myelosis or lymphoma,
destruction of red blood cells or their damage and release of hemoglobin,
deficiency of certain vitamins in the body,
iron deficiency,
massive blood loss.

However, it must be said that such a situation is quite rare and, as a rule, is the result of a laboratory error.

The erythrocyte distribution index is reduced: what does this mean and what to do? Reduced RDW: pathology and norm

Red blood cell distribution index (RDW) is a very important factor during a complete blood count. This indicator demonstrates the size and shape of red blood cells.

Red blood cells perform the transport function, thereby assisting in the penetration of oxygen into all tissues and organs and at the same time taking away toxins and carbon dioxide accumulated in the cells. In their normal state, red blood cells are approximately the same size, which allows them to quickly stick together, forming blood clots.

The indicator of red blood cells in the blood may reflect the presence of pathological processes in the body, especially if the sizes of these cells vary significantly. Next, we will talk about in what situations the erythrocyte distribution index decreases, how this manifests itself and what it indicates.

Reduced RDW: norm and pathology

A person in good health has red blood cells of the same shape, density and color. In case of deviation, especially in the presence of autoimmune diseases or oncology, the failure occurs at the level of microcells, when young cells do not receive a certain number of components, which, in fact, inhibits their performance. Thus, anemia occurs - a pathology during which the body does not receive the required amount of oxygen, in other words, the metabolic function in red blood cells is disrupted.

What does RDW mean in a blood test?

During a general blood test, the erythrocyte distribution index is determined. If the presence of a specific disease is suspected, a blood test is prescribed to determine only this indicator.

Most often, the width of the distribution of red blood cells by volume is determined together with the MCV indicator. This is the average volume of red blood cells. This happens because these indices (in quantity and volume) are closely related to each other and help in determining the type of anemia.

It happens that the erythrocyte distribution index is reduced. What does it mean? The thing is that for a qualitative judgment about the state of red blood cells, not only their concentration in the blood is important, but also their shape. An increased distribution of red blood cells is observed in 1 of the cases, but if the RDW index is reduced, which is much less common, we are talking about the presence of serious problems in the human body.

A blood test to determine the erythrocyte distribution index can be carried out both during medical examinations (routinely) and as prescribed, if there are suspicions of any abnormalities in the hematopoietic function. The analysis is required before surgery, during pregnancy and in childhood.

Why is it necessary to do an RDW analysis?

It was already mentioned above that the index of distribution of red blood cells in the blood makes it possible to conduct a qualitative assessment of the composition of red blood cells, taking into account their size.

But why is this necessary? The thing is that these cells are very similar to each other, which gives them the opportunity to replace each other or form blastulas. An increase in cell size entails an increased need for nutrition and, in addition, this means that their life expectancy is reduced. All this directly affects the overall indicator of red blood cells in the blood and the human condition.

When a large number of red blood cells die, iron is released and more bilirubin becomes available, which puts increased stress on the liver, and as a result, it cannot process these substances.

The RDW index is directly related to the pathological process, during which the dimensions of erythrocytes change (anisocytosis). This condition is a complex chemical process that causes all blood cells to suffer.

How is it calculated?

The RDW indicator is calculated as a percentage, the norm of which is considered to be the limit from 11.5 to 14.8. The red blood cell distribution index is determined using a mathematical equation that represents the ratio of modified red blood cells to their total mass.

Nowadays, laboratories use computer technologies that make it possible to calculate the percentage of deviation from the established norm. The calculation results are presented in the form of a histogram depicting a curve that indicates probable changes in the dimensions of red blood cells.

Normal indicators

The norms of the erythrocyte distribution index depend on gender, age and the presence of certain conditions that occur in the human body. For children under one year of age, the normal rate is 11.5-18.7%. At one year of age and older, the values tend to the generally accepted norm of 11.5-14.5%.

For the female half of humanity, the upper limit shifts to 15.5%, since their hormonal levels change too often: during pregnancy, lactation, taking oral contraceptives, menopause.

For analysis, blood is taken on an empty stomach in the morning (before 9 am). It is very important that before this procedure the person does not take any medications and is in a balanced internal state.

Raising RDW

The RDW level can be elevated in some situations. The most common cause of this pathology is iron deficiency anemia. The indicator can change at different stages of pathology development, which is clearly reflected in the histogram of red blood cells:

The initial stage of anemia development is characterized by normal indices, but hemoglobin will be greatly reduced. This is the result of healthy functioning of the spinal cord.
The next stage of development in the histogram will show an increase in RDW. When there are problems with hemoglobin, indicators such as the average concentration and content of hemoglobin in a blood cell and the average volume of red cells decrease.

When treating IDA, it is necessary to normalize the level of concentration of iron-containing protein and its characteristics in the human blood.

What do the reduced numbers mean?

Patients often ask what this means: “red blood cell distribution index is reduced.” Since the erythrocyte distribution index cannot be assessed without a volume indicator, it is necessary to familiarize yourself with all the options for underestimated indicators and their relationship:

RDW is low and MCV is below average - indicating problems with the spleen and liver.
RDW is lowered, and MCV is higher than the normal level - indicates the presence of oncological pathologies, mainly the development of metastases in the bone marrow.

The fact that the erythrocyte distribution index RDW sd is reduced, from a biological point of view, cannot, in principle, be observed. For this reason, most often the patient is offered to donate blood again, observing the following conditions:

stop smoking and drinking alcohol for 24 hours before blood sampling;
do not take any medications before the analysis;
Avoid eating smoked and salty foods the day before.

In the case when the erythrocyte distribution index RDW sd is indeed reduced, which is necessarily confirmed by deviations from the norm in the MCV indicator, then this indicates the occurrence of certain pathologies. These include:

Hypochromic microcytic anemia - sometimes also called anemia. A condition in which irregularly shaped red blood cells die because they have no biological value in the body.
Malignant tumors - usually in this case we are talking about mastopathy, bone marrow and lung cancer.
Hemolysis of red blood cells is a process during which red blood cells die without reaching their target. As a result, active hemoglobin is released.

Causes

So, the erythrocyte distribution index is reduced - what does this mean? There are several reasons that can reduce the RDW indicator:

Acute blood loss due to injuries and pathological bleeding.
Frequent operations.
A metabolic disorder during which the food consumed is not completely digested.
Hormonal imbalance, which most often occurs in women.
Deficiency of B vitamins and iron in the body.
Blood diseases characterized by rapid destructive processes.

What measures to take?

What to do when the red blood cell distribution index is low?

A highly qualified doctor during a consultation will most likely ask the patient to take the test again, because the RDW indicator is almost never underestimated. Because this suggests that all cells are ideal in their parameters, but this cannot happen in principle. If the indicator is confirmed by repeated analysis, then a full examination of the body’s condition is carried out, paying special attention to oncological examinations.

Preventive measures

You can prevent a reduced RDW by following these simple rules:

The diet should be balanced, which includes plenty of fresh fruits, lean meats and vegetables.
It is recommended to breathe fresh air as often as possible.
An active lifestyle will help prevent a decrease in the RDW index.
It is very important not to skip routine medical examinations, during which most often serious deviations from the norm are detected that do not have external symptoms.

As a result, we learned that the red blood cell distribution index reflects their dimensions relative to each other and makes it possible to learn about their biological value. A decrease in RDW is very rare, but if the erythrocyte distribution index is decreased, this means that various pathologies may be present.

The index is calculated based on the results of a general blood test, but can only be fully valid in conjunction with the MCV indicator, since they are closely interrelated.

The circulatory system is the most important part of the human body. Blood circulates throughout the body and comes into contact with all organs and tissues in the body. It is through a blood test that the doctor can determine the condition of its main indicators and what this means.

Quantitative and qualitative indicators of various types of blood cells are assessed. When studying red blood cells, the designations RDW, RDW CV, MDV and others are often found. Testing for RDW, what is it in a blood test?

Most of the parameters of the blood test are clear to patients. Indicators such as white blood cells, glucose, cholesterol and others are well known, and their normal levels are indicated next to the patient’s result. A simple mathematical comparison of numbers allows you to make sure that the tests are within normal limits. But what is RDW?

RDW blood test and erythrocyte distribution index are the same value. The presence of deformed red blood cells (erythrocyte anisocytosis) is examined, and the indicator reflects the uniformity of red blood cells. Normally, red blood cells should be approximately the same size so that, if necessary, one red blood cell replaces another and performs the same functions.

If some of the cells are large, this is a violation.

They require more nutrition to survive and their lifespan is shortened. Also, macro cells are often larger in size than the diameter of the capillaries and cannot circulate through the circulatory system; they are disposed of.

The RDW blood test measures the ratio of misshapen or enlarged red blood cells to normal-sized red blood cells. There are two types of indicators RDW CV and RDW SD. The first value (RDW CV in blood tests) shows the percentage distribution of cells by size. The second reflects their standard deviation, that is, the difference in size between the smallest and largest red blood cells present in the blood sample.

Indications for analysis

A referral for a general blood test can be issued by any doctor, from a local physician to a highly specialized physician. An erythrocyte anisocytosis test is performed as part of an annual physical examination or as indicated. As part of a routine examination, RDW is not always examined in blood tests. This indicator is checked if the patient has the following symptoms:

Increased temperature for no apparent reason (colds and other diseases)
Constant sleepiness, even if the patient gets enough rest at night
Increased sweating, regardless of heat
Frequent and rapid fatigue, lack of strength for daily activities
Sudden mood swings, irritability and emotionality for no apparent reason
In some cases, yellowing of the skin is observed

Accepted standards

The RDW norm for adult men and women is the same and ranges from 11.5–14.5%. In children, the test for erythrocyte anisocytosis shows different results. For newborns, the norm is 14.9–18.7%, which is associated with stress during childbirth and adjustment to life outside the mother's body. In children over the age of six months, the level of RDW in the blood is in the range of 11.6–14.8%. As you grow older, the RDW coefficient approaches the “adult” indicator.

The interpretation of the analysis is carried out by the attending physician, a qualified specialist who is familiar with the patient’s medical history and takes into account all factors. A deviation from the accepted norm of more than 15% indicates disturbances in the functioning of the body. In some cases, the patient is given a second referral for testing.

Increased rate

A high level of RDW on a blood test may indicate disease or pathology. Often the indicator differs from the norm due to a lack of certain nutrients and vitamins. Main causes of violation:

Oncological diseases, tumor development
Liver diseases in the chronic stage
Alzheimer's disease
Diseases of the cardiovascular system
Anemia of various nature (hemolytic, microcytic, megaloblastic, iron deficiency), among all patients it is especially important to identify this condition in pregnant women
Iron deficiency, which affects hematopoietic function
Deficiency of vitamins B9 and B12
Folic acid deficiency
Alcoholism

Reduced rate

Sometimes the parameters being studied indicate that the RDW in the blood test is low. RDW should be considered in conjunction with mean cell volume, or MCV, to determine the causes of red blood cell production below normal. Only the relationship between these two indicators can provide the doctor with the necessary information for diagnosis.

RDW and MCV have been reduced. This situation may indicate problems with the spleen (disposes of damaged red blood cells) or liver (breaks down toxins and other substances).
The RDW test is low and the MCV level is high. This condition can occur when the bone marrow is damaged by cancer cells. Perhaps a malignant tumor developed in the body for a long time, unnoticed by doctors, and metastases reached the bone marrow.

The width of the distribution of red blood cells by volume below normal is extremely rare. A low rate indicates serious health problems, but in 99.9% of cases this result is a consequence of laboratory errors and the influence of external factors. Incorrect settings, equipment failure, or violation of rules for storing and processing a blood sample can distort the result of the study. If there was no error when analyzing the indicator of erythrocyte anisocytosis, then the reasons for the low level of RDW in the patient’s blood may be the following:

The result of surgery, especially if any organ or part thereof has been removed.
Extensive blood loss due to injury or medical condition. Internal gastric or uterine bleeding is considered especially dangerous. In such cases, blood loss occurs very quickly, which reduces the patient's chances of survival.
Blood donation.
Disorders of the body's metabolic processes that make it impossible for the normal absorption of nutrients, minerals and vitamins from food.
Hormonal imbalance. Often the level of red blood cell distribution is reduced in women during pregnancy, puberty or menopause. Also, the amount of hormones can fluctuate as a result of taking medications, such as hormonal contraceptives.
Deficiency of vitamin B, folic acid and some other substances.
Some pathological conditions that lead to the loss of biological functions of red blood cells.

You don't have to be a doctor to understand what RDW is in a blood test. But deciphering the RDW study should only be carried out by an experienced and qualified specialist. The ratio, when properly examined, can indicate the presence of various serious diseases, the treatment of which should begin immediately. Or the test result may indicate that the patient is completely healthy.

In contact with

The RDW indicator can be found in the results of a clinical blood test. Like many others, RDW is important for diagnosing human health. Let's take a closer look at it.

heat;
lack of strength, general fatigue of the body;
excessive sweating;
constantly tends to sleep;
emotional mood swings;
sometimes yellowing of the skin.

Details about the blood test for RDW (CV)

If you constantly feel the above symptoms, then it is better to consult a doctor.

Normal values

The norm for adults and children is different. Deviations can be up or down and indicate a health problem.

If deviations from normal values are more than 15%, we can talk about the presence of certain diseases. Moreover, the higher the indicator, the greater the discrepancies in the sizes of red blood cells.

Reasons for the increase

Indicators may increase if a disease or some other serious pathology develops in the body. The main reasons include:

iron deficiency in the body;
chronic liver damage;
cardiovascular diseases;
Alzheimer's disease;
oncology;
lack of vitamins B9 and B12, etc.

We can also talk about the reasons for the increase in RDW when a person suffers from various types of anemia, that is, anemia. These include anemia: microcytic, hemolytic, megaloblastic, etc. This index also allows timely detection of iron deficiency anemia during pregnancy in women.

How much does the analysis cost?

The RDW indicator is included in the results. Therefore, the cost of this is not expensive. Prices vary from region to region, but generally vary from 200 before 600 rubles

For example, in Moscow, the Invitro laboratory conducts a general blood test for 395 rubles

The value of the analysis on the RDW indicator is very large. Thanks to it, it is possible to diagnose the disease in time and begin timely treatment. Remember, only an experienced doctor will be able to correctly determine the symptoms of the disease and its occurrence based on the results obtained. When deciphering any analysis, there are many subtleties that only professional medical professionals know.