If the width of the distribution of erythrocytes is increased. RDW in a blood test - what is it

These red blood cells carry out a transport function, helping to deliver oxygen to all tissues and organs, taking away carbon dioxide and toxins accumulated by cells. Normally, their sizes are approximately the same, which allows them to quickly stick together under certain conditions, forming blood clots.

Red blood cells can indicate the presence of pathologies in the body, especially if their dimensions are very different from each other. In what cases the distribution index is lowered, what this indicates and how it manifests itself, we will find out further.

Decrease in RDW: pathology and norm

In a healthy person, red blood cells have the same shape, density and color. In cases of deviations, especially in autoimmune diseases and oncology, there is a failure at the microcellular level, when newly formed cells do not receive certain components, and in fact are not able to perform their functions. From here, anemia develops - a pathological condition in which the body does not receive the right amount of oxygen, that is, the metabolic function of red blood cells is disturbed.

The distribution index of erythrocytes is determined during a general blood test. In some cases, if a specific disease is suspected, only this index can be determined in the analysis. In most cases, the width of the RDW is determined along with the mean MCV, since these indices (by volume and number) are interrelated and help determine the type of anemia. The fact is that for a complete assessment of the state of erythrocytes, not only their shape is important, but also their quantity in the blood. And if increased rates occur with a frequency of 1 per person, then reduced values \u200b\u200bare extremely rare and always indicate serious health problems.

A blood test for the determination of RDW can be performed both routinely (during medical examinations) and according to indications, when there are suspicions of abnormalities in the hematopoietic function. Without fail, the analysis is performed before surgery, in childhood and during pregnancy.

Why is RDW needed?

But what does it give? The fact is that erythrocytes are similar to each other like twin brothers, which allows them to replace each other at the right time or stick together into blastulae. If the cells increase in size, their need for nutrition also increases, respectively, their life expectancy is short. This in turn affects the overall level of red blood cells and human health.

The more cells die, the more bilirubin and iron are released, which in turn represents an increased load on the liver, which will malfunction, unable to cope with the processing of these substances.

The RDW index is directly related to anisocytosis, a pathological process in which the shape of red blood cells changes, which affects their volume and size. Anisocytosis is a complex chemical process that affects all blood cells.

We suggest watching a video on the topic

How is it determined?

It is determined using a mathematical formula, in the form of a ratio of modified erythrocytes that exceed the maximum allowable volumes to the total mass of erythrocytes.

To date, laboratories use computer technology to determine the percentage of deviation from the norm, without doing manual calculations. The output data is presented in the form of a histogram, which displays a curve indicating possible modifications of red blood cells.

What do the results depend on?

The norms are determined depending on age, gender and the presence of physiological processes occurring in the body. For children of the first year of life, an indicator of 11.5-18.7% is considered the norm. After a year, the digital values tend to the generally accepted norm - 11.5-14.5%. In women, the upper limit can shift up to 15.5%, which is explained by frequent changes in the hormonal background: pregnancy, breastfeeding, taking hormonal contraceptives, menopause.

Index variations

In a more detailed in-depth study of the erythrocyte distribution index index, two values are considered:

RDW-SD - defines the standard deviation from the norm, expressed in femtoliters. The indicator has nothing to do with MCV, since it shows the quantitative value of the difference between the largest and smallest cells.
RDW-SV - shows how much the volume of erythrocytes differs from the average. It is defined as the percentage of all deformed cells to the total erythrocyte mass.

What do the low values mean?

Since it is impossible to fully evaluate RDW without MCV, all options for lower values should be considered when these two indices are interconnected:

RDW is low and MCV is below average - a problem with the liver and spleen.
RDW is low, and MCV is higher than normal - the presence of oncological diseases, mainly with metastases in the bone marrow.

A decrease in the distribution of erythrocytes cannot be manifested in principle, if we consider this indicator from a biological point of view. Therefore, in medical practice, when rather low values are detected in 99.9% of all cases, the patient is offered to retake blood, having previously fulfilled all the conditions:

do not smoke or drink alcohol 24 hours before blood sampling;
do not use medications before analysis;
limit the intake of salty and smoked foods the day before.

In the case when the RDW is really below the norm, which is confirmed by the unsatisfactory analyzes of his "colleague" MCV, this may indicate the development of diseases such as:

Microcytic anemia - in the common people "anemia", when, due to irregular shapes, red blood cells quickly die off, without representing any biological value for the body.
Malignant neoplasms - usually refers to diseases such as mastopathy, bone marrow cancer and lung cancer.
Extensive hemolysis is a process in which red blood cells are destroyed before they reach their target. As a result, active hemoglobin is released.

Causes

There are a number of reasons that could provoke the development of such a manifestation, as a reduced RDW:

Large blood loss in traumatism and pathological bleeding. The most dangerous are uterine and gastric internal bleeding, in which the blood leaves at a rapid pace, reducing the chances of survival.
Frequent surgical interventions, especially when removing any organ or part of it.
Incorrect metabolism, in which the food consumed is not completely digested and assimilated, but partially or completely undergoes fermentation and decay processes.
Hormonal imbalance, which is more common among the female half of the population.
Lack of iron and B vitamins in the body.
Pathologies of the blood, which are characterized by rapid destructive processes, as a result of which erythrocytes completely lose their biological functions.

How is it manifested?

A patient with a low RDW will have all the symptoms of anemia:

lethargy and apathy;
fast fatiguability;
frequent dizziness, especially with sudden movements;
constant fatigue even after a long rest;
severe shortness of breath with the addition of chest dry cough for no reason;
increased heart rate (tachycardia);
increased blood pressure (if overweight).

Such clinical manifestations are quite easy to explain. Small cells bring less oxygen to tissues and organs, from which the latter begin to suffer, since all natural biological processes (oxidation and reduction) do not occur without oxygen. Large ones are generally not able to retain oxygen molecules on their surface, from which microcytic anemia develops.

The nerve cells responsible for all impulses in the body will be the first to suffer, from which the above symptoms appear.

What to do?

At a consultation with a doctor, most likely he will ask to retake the analysis, since the distribution index of erythrocytes is practically never lowered. This means that all cells are ideal in their parameters, which cannot be in principle. If all factors that could affect the inaccuracy of the results are excluded and the indicator is repeated, a complete examination of the body is carried out, paying special attention to oncological research.

Prevention

You can prevent this process by following simple rules:

Eat a balanced diet, including plenty of fresh vegetables, fruits, and lean meats.
Be outdoors more often.
To live an active lifestyle.
Do not neglect scheduled medical examinations, where, according to statistics, serious pathologies that do not have external signs are most often detected.

Thus, the distribution index of erythrocytes shows their size relative to each other, which makes it possible to determine their biological value. Reduced rates are extremely rare, but can fully indicate the presence of various diseases. The index is determined during a general blood test, but it has full power only when it is jointly calculated with the MCV index, the indicators of which are interconnected.

This percentage is relative, so in many cases it is not calculated with a detailed blood test.

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Rdw in the blood test is lowered

What it is

Laboratory research rdw

Norm

Deciphering and meaning of the RDW indicator in the general blood test

The most important indicators in the study of a blood sample are considered to be the level of hemoglobin, the number of leukocytes and platelets.

Modern hematology devices also determine other values, for example, the width of the distribution of erythrocytes (red cells distribution width). The RDW coefficient in a blood test is inextricably linked to the mean corpuscle value.

A detailed decoding of blood biochemistry allows you to establish a more accurate diagnosis, especially when determining the type of anemia and related diseases. RDW as a result of the analysis may indicate anicitosis if red blood cells are produced in the blood that are larger or smaller than normal. The calculation of this indicator provides more information with reduced hemoglobin and microcytic anemia (reduction in the size of red cells).

RDW value

The distribution width is calculated during a complete venous blood count to determine the homogeneity of red blood cells. The word "width" in this term is sometimes misleading. RDW stands for variation in red blood cell size. This value is calculated by comparing their volume.

Electronic devices are able to evaluate the impulses that produce blood cells. The stronger the impulse, the larger the erythrocyte. Approximate variation in the size of healthy erythrocytes is 10.2–14.6%. It is important to note that when using different devices, the decoding of RDW may differ, so the reference value of the norm is indicated on the test result.

Clinical use

The coefficient helps diagnose various conditions.

Nutrient deficiencies: iron, folate, vitamin B12. In these anemias, RDW rises.
The width of the distribution makes it possible to distinguish thalassemia from iron deficiency anemia. With thalassemia, this figure is within the normal range, and with a lack of iron, it is overestimated. However, additional tests are required to establish a more accurate diagnosis.
With a deficiency of vitamin B12 and folic acid, the size of red blood cells may increase (macrocytic anemia). But macrocytosis is a characteristic feature in other diseases as well. The distribution width of red blood cells provides additional information for a correct diagnosis.
The variation in the size of red blood cells above the norm makes it possible to suspect some disorders in the early stages.
Among patients with oncological and cardiovascular diseases, this indicator plays a large role in the early detection of complications that can lead to death.

Relationship with MCV

In the treatment of anemia and other blood disorders, RDW is related to MCV, the mean volume of blood cells. Essentially, RDW is the MCV ratio. Its increased value reflects the greater heterogeneity of the MCV (anicytosis), which usually occurs when the degradation or maturation disorder of the blood cells.

Comparison of two indicators gives specialists information about a particular deviation in the state of the blood. Different combinations of RDW and MCV values may indicate anemia, thalassemia, chronic liver disease.

Increased RDW

With a normal MCV, early iron deficiency anemia, liver disease, and sickle cell disease can be diagnosed.
A low level indicates iron deficiency anemia, some forms of thalassemia.
At a high value, megaloblastic anemia (lack of vitamin B12, folic acid), myelodysplastic syndrome, and chronic liver diseases are diagnosed.

Normal RDW

With a low MCV, abnormal E hemoglobin or anemia may be detected as a symptom of a chronic disease.
A high value occurs during chemotherapy, with chronic disorders in the liver, myelodysplasia.

What should be a normal RDW

The optimal value of the coefficient is 13%. Variations within 11-14% are also considered the norm. Some hematology machines have their own, slightly different, rate that is used to evaluate test results. Usually this value is indicated in the blood test for comparison.

As noted earlier, a normal RDW level alone does not provide complete information. It is interpreted in relation to the MCV.

Low RDW

The RDW is rarely below 10.2%. This means that erythrocytes are uniform and practically do not differ in size from each other.

Usually, this condition is a sign of macrocytic anemia, a disorder in which there are not enough red blood cells in the blood, and those that are, are larger than normal. Another cause of low RDW is microcytic anemia. With this disease, the size of red blood cells is noticeably smaller than normal.

Uniformity in the size of erythrocytes is observed in such diseases:

The coefficient is considered increased when the indicator is more than 15%. This means that red blood cells vary greatly in size.

There are many possible causes for this condition. To determine the most likely diagnosis, the RDW is compared with the MCV.

High MCV

Given that MCV is the average volume of space that each blood cell occupies, then an increased level of both indicators may indicate several possible deviations in the state of the body.

Liver disease

The liver is the largest internal organ in the human body, which produces the substances necessary for the body, filters the blood, and removes harmful chemicals. The condition of the liver worsens with alcoholism, as evidenced by an elevated level of RDW.

Hemolytic anemia

A disease in which red blood cells die or are destroyed earlier than their healthy life cycle suggests.

Megaloblastic anemia

Large oval erythrocytes with an underdeveloped nucleus and a short life cycle appear in the blood. Usually this condition occurs due to a lack of folic acid or vitamin B12 in the person's diet or impaired absorption of these substances.

Vitamin A deficiency

The body must have a minimum amount of vitamin A for cell synthesis in conjunction with vitamin B12.

Low MCV

In other cases, the mean volume of erythrocytes is reduced, while the width of the distribution is still above normal. This may be a sign of some less common anemia or iron deficiency conditions.

Decreased hemoglobin level

Hemoglobin is present in red blood cells. It helps deliver oxygen to the cells of the body. Iron is necessary for the synthesis of hemoglobin, so a deficiency of this microelement leads to a decrease in the level of hemoglobin in the blood.

Usually, iron deficiency anemia is caused by insufficient iron in the diet, poor absorption of iron from food or dietary supplements.

Intermediate form of thalassemia

Intermediate thalassemia is a blood disease in which the synthesis of one or more components of hemoglobin is impaired. As a result, blood cells are fragmented (broken into smaller particles).

If the RBC fragments are markedly different in size but do not take up more space, this may show up in the analysis as a low MCV with a high RDW.

Normal MCV

An elevated RDW with a normal MCV can be caused by:

the initial stage of iron deficiency anemia, leading to a decrease in hemoglobin;
a decrease in the level of vitamin B12 or folic acid in the body, which is a prerequisite for macrocytic anemia.

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What does a blood test for RDW mean?

A complete blood count is a universal medical indicator of human health. It can be used to find out which group the disease belongs to, if there are doubts between several similar, but from different groups; learn about possible complications; determine the body's response to drug treatment, as well as track the dynamics of treatment (for example, do a blood test for RDW).

At the same time, in the general blood test, there are mandatory indications - the number of basic blood cells, hemoglobin (a component of erythrocytes), ESR in the blood - the erythrocyte sedimentation rate. At the request of the doctor, they can add a leukocyte formula - the percentage of all types of leukocytes in a milliliter of blood, various indicators for platelets and erythrocytes. Most indicators are determined specifically for erythrocytes, since these elements are the most basic for human blood. And so we will analyze with you what a blood test for RDW means, why it is increased and decreased, and how blood is deciphered.

What it is

A person who is ignorant of medical terminology when viewing a blood test for RDW is likely to ask the question: what is RDW in a blood test? It is easier for a doctor to answer this question: RDW is an indicator in the blood indicating the heterogeneity of red blood cells.

Erythrocytes in the blood exist in certain norms - volume, diameter, amount of hemoglobin, etc. In abnormal conditions, red blood cells occur in different sizes, and the difference in volume between the largest and smallest is called heterogeneity or RDW.

Laboratory research rdw

Norm

In the body, the norm of RDW in the blood will almost always be close to zero, because in a completely healthy body there are all conditions for the normal existence and synthesis of red blood cells.

Unfortunately, in the harsh reality, many people experience some health problems - almost every city dweller has anemia - a lack of iron or hemoglobin in red blood cells, which will affect the volume of this cell, not to mention other conditions of people.

This phenomenon of different-sized erythrocytes in the blood, scientists called anisocytosis in the blood.

At the same time, in the normal blood RDW, the volumetric size of erythrocytes is 6.9-7.4 microns, and other sizes can be called pathologies:

RBC volume< 6,9 мкм – микроциты (с латинского – маленькие клетки). В норме крови на них должно приходиться меньше 15% всех эритроцитов.
6,9 < объем эритроцита < 7,4 – нормоциты (нормальные клетки). В норме на них должно приходиться не менее 70% всех эритроцитов;
7,4 < объем эритроцита – макроциты (большие клетки). В норме на них должно приходиться меньше 15% всех эритроцитов

The norm of RDW in a blood test in an adult is 11-14%.

Why is an analysis ordered?

Usually, a blood test for RDW is included in the list of mandatory tests during medical examinations, since it can identify the early stages of diseases, but in some cases the doctor may prescribe blood donation for this indicator separately.

Before surgery, it is very important for the doctor to know the RDW in the patient's blood test, as it can show the presence of anemia. And in some cases, the result of an RDW test may be a contraindication for surgery or the drug used during the intervention.

Relegation and promotion

Normally, in a blood test for RDW, the doctor will see more than 70% of normocytic cells. Other indications can be considered deviations that appear as a result of various diseases. Usually, a blood test for RDW is either high or low.

So, if a lowered RDW is detected in a blood test, one can judge the presence of various types of anemia in a person. At the same time, this indicator is important for diagnosis, so with a normal average volume of erythrocytes and a reduced RDW, one can judge the presence of microcytic anemia.

If the average volume of red blood cells is lowered, and the RDW of the blood, on the contrary, is normal, then the patient is prone to hemorrhage (the scientific name for hemorrhages), thalassemia disease (a genetic disorder that affects the synthesis of hemoglobin, which affects the synthesis of red blood cells), or processes associated with the complete removal of the spleen - places of death of erythrocytes.

A patient with a reduced RDW will experience chronic fatigue, easy fatigue, lethargy and drowsiness, sometimes rapid breathing and severe shortness of breath. The clinical picture will resemble anemia. This is because small-sized red blood cells will deliver less oxygen to the tissues than normal-sized red blood cells. The nervous system will first of all “suffer” from this, which will manifest itself in the symptoms described above.

So, when using iron-containing drugs, erythrocyte cells may slightly increase due to new iron, but this will manifest itself in analyzes massively only a month and a half after the start of treatment. Therefore, it is important to take all the prescribed tests on time, because thanks to this, the doctor will be able to track the dynamics of treatment.

Constant fatigue with reduced rdw

How to prepare

Preparing for an RDW blood test is no different than preparing for a CBC. The doctor recommends that the patient observe the hospital regimen, and if the treatment is carried out on an outpatient basis, then follow the following general recommendations:

Blood is taken on an empty stomach, in the morning.
A week before the day of the RDW test, it is very important to give up alcoholic beverages.
During the same week, it is recommended to adhere to the principles of the diet, that is, the exclusion from the diet of fried, spicy, fatty and canned foods.
If possible, 3 days before the donation, exclude drugs that especially affect the level of iron in the blood. If it is impossible to cancel, the attending physician informs the patient about this, and also indicates this on the form and referral for tests.
In the morning, it is advisable to eat only light food without sugar. Coffee and strong black tea will also negatively affect the results of the analysis.
Do not smoke for 3 hours before the test.
15 minutes before the test, it is recommended to sit near the office and relax.

All these recommendations are due to the fact that if this schedule is not observed, a sufficiently large number of erythrocytes will be associated with other compounds (an erythrocyte in combination with glucose from food forms glycated hemoglobin, which manifests itself differently in the analysis, similarly - other compounds).

When smoking or drinking strong drinks, a very large number of erythrocytes with oxygen goes to peripheral tissues, which also affects the blood test results.

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The distribution index of erythrocytes is lowered: what does it mean and what to do? Decrease in RDW: pathology and norm

The Red Blood Cell Distribution Index (RDW) is a very important factor during a complete blood count. This indicator shows the size and shape of red blood cells.

Red blood cells realize the function of transportation, thereby assisting in the penetration of oxygen into all tissues and organs, while taking away toxins and carbon dioxide accumulated in cells. In the 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 can reflect the presence of pathological processes in the body, especially if the sizes of these cells vary significantly. Next, we will talk about the situations in which the red blood cell distribution index decreases, how it 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 the event of a deviation, especially in the presence of autoimmune diseases or oncology, a failure occurs at the level of microcells, when young cells do not receive a certain number of components, which, in fact, slows down their performance. Thus, anemia occurs - a pathology during which the body does not receive the right amount of oxygen, in other words, the metabolic function in red blood cells is impaired.

What does RDW mean in a blood test?

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

Most often, the width of the distribution of erythrocytes by volume is determined in conjunction with the MCV index. This is the average volume of erythrocytes. This happens because these indexes (by number and volume) are closely related and help in determining the type of anemia.

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

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

Why is it necessary to do an analysis on RDW?

It has already been said above that the distribution index of erythrocytes in the blood makes it possible to conduct a qualitative assessment of the composition of red blood cells, given 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 blastulae. An increase in cell size entails an increased need for nutrition and, in addition, this means that their lifespan is reduced. All this directly affects the overall rate of red blood cells in the blood and the human condition.

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

The RDW index is also directly related to the pathological process during which the dimensions of red blood cells 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 the limit from 11.5 to 14.8. The distribution index of erythrocytes is determined using a mathematical equation, which is the ratio of modified red blood cells and their total mass.

At present, laboratories use computer technology that allows you to calculate the percentage of deviation from the established norm. The results of the calculation are presented in the form of a histogram depicting a curve that indicates the likely changes in the size of red blood cells.

Normal performance

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 old, the normal rate is 11.5-18.7%. At the age of one and older, the values tend to the generally accepted norm, which is 11.5-14.5%.

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

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

Raise RDW

The level of RDW in some situations is elevated. The most common cause of this pathology is iron deficiency anemia. The indicator can change at various stages of the development of the pathology, which clearly reflects the histogram of erythrocytes:

The initial stage of the development of anemia 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 the blood cell, the average volume of red cells decrease.

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

What do low scores mean?

Patients often ask what it means: "erythrocyte distribution index is lowered." Since the erythrocyte distribution index cannot be estimated without a volume indicator, it is necessary to familiarize yourself with all options for underestimated indicators with their relationship:

RDW is low, and MCV is below average - indicates the presence of 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 bone marrow metastases.

The fact that the distribution index of erythrocytes 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 within 24 hours before blood sampling;
before the analysis, do not take any medications;
refuse to eat smoked and salty foods the day before.

In the case when the distribution index of erythrocytes RDW sd is really lowered, which is necessarily confirmed by deviations from the norm of the MCV indicator, 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 the process during which red blood cells die before reaching their target. As a result, active hemoglobin is released.

Causes

So, the distribution index of erythrocytes is lowered - what does this mean? There are several reasons that can lower the RDW:

Acute blood loss in trauma and pathological bleeding.
Frequent operations.
A metabolic disorder in which the food consumed is not completely digested.
Hormonal failure, which is most common in women.
Deficiency in the body of B vitamins and iron.
Blood diseases characterized by rapid destructive processes.

What measures to take?

What to do when the erythrocyte distribution index is lowered?

A highly qualified doctor at the consultation will most likely ask the patient to take the test again, because the RDW indicator is almost never underestimated. Since this suggests that all cells are ideal in their parameters, and this, in principle, cannot be. If the indicator is confirmed upon re-analysis, then a complete study of the state of the body is carried out, paying special attention to oncological examinations.

Preventive measures

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

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

As a result, we learned that the distribution index of erythrocytes reflects their dimensions relative to each other and makes it possible to learn about their biological value. A decrease in the RDW is very rare, but if the distribution index of erythrocytes is low, this means that various pathologies are possible.

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

The Red Blood Cell Distribution Index (RDW) is a very important factor during a complete blood count. This indicator shows the size and shape of red blood cells.

How is it calculated?

Normal performance

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

Raise RDW

The initial stage of the development of anemia 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 the blood cell, the average volume of red cells decrease.

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

What do low scores mean?

RDW is low, and MCV is below average - indicates the presence of 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 bone marrow metastases.

stop smoking and drinking alcohol within 24 hours before blood sampling;
before the analysis, do not take any medications;
refuse to eat smoked and salty foods the day before.

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 the process during which red blood cells die before reaching their target. As a result, active hemoglobin is released.

Causes

So, the distribution index of erythrocytes is lowered - what does this mean? There are several reasons that can lower the RDW:

Acute blood loss in trauma and pathological bleeding.
Frequent operations.
A metabolic disorder in which the food consumed is not completely digested.
Hormonal failure, which is most common in women.
Deficiency in the body of B vitamins and iron.
Blood diseases characterized by rapid destructive processes.

What measures to take?

What to do when the erythrocyte distribution index is lowered?

Preventive measures

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

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

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

This indicator shows the size and shape of red blood cells.

Reduced RDW: norm and pathology

What does RDW mean in a blood test?

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

Why is it necessary to do an analysis on RDW?

It has already been said above that the distribution index of erythrocytes in the blood makes it possible to conduct a qualitative assessment of the composition of red blood cells, given their size.

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

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

How is it calculated?

Normal performance

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

Raise RDW

The initial stage of the development of anemia 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 the blood cell, the average volume of red cells decrease.

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

What do low scores mean?

RDW is low, and MCV is below average - indicates the presence of 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 bone marrow metastases.

stop smoking and drinking alcohol within 24 hours before blood sampling;
before the analysis, do not take any medications;
refuse to eat smoked and salty foods the day before.

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 the process during which red blood cells die before reaching their target. As a result, active hemoglobin is released.

Causes

So, the distribution index of erythrocytes is lowered - what does this mean? There are several reasons that can lower the RDW:

Acute blood loss in trauma and pathological bleeding.
Frequent operations.
A metabolic disorder in which the food consumed is not completely digested.
Hormonal failure, which is most common in women.
Deficiency in the body of B vitamins and iron.
Blood diseases characterized by rapid destructive processes.

What measures to take?

What to do when the erythrocyte distribution index is lowered?

Preventive measures

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

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

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

The distribution width of erythrocytes (RDW index): what is it, the norm, 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 erythrocyte anisocytosis, which is included in the list of all components of the general blood test (CBC), that is, this parameter is usually not assigned on its own and not tested in the laboratory.

So what does such an erythrocyte index as RDW mean, what information does it carry to specialists and why is it used?

Distribution of erythrocytes by volume

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

Large cells - macrocytes;
Just giants - megalocytes;
Lilliputian cells, which are called microcytes.

And here it is not necessary to be a specialist in this field in order to understand that red blood cells 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 coagulation, etc. .), which, of course, 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 erythrocytes. In order to find out how many in the general population of erythrocytes there are bizarre shapes characteristic of a particular type of anemia, and calculate the width of the distribution of erythrocytes (erythrocyte index RDW).

Many laboratory diagnostic physicians and hematologists take RDW as a coefficient of variation, indicating how much the average 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 mean volume of red blood cells, and the MCV index corresponds to their mean volume.

Is it always possible to believe the norm?

The range of normal values of the distribution of erythrocytes by volume varies within 11.5 - 14.5% (in children under six months, the norm, in general, differs markedly and ranges from 14% to 18.7%, although from 6 months the values of the indicator are already begin to aspire to the norm of adults).

An elevated RDW in a blood test indicates the degree of heterogeneity (heterogeneity) of red blood cell populations or indicates the presence of several blood cell populations in the sample, which occurs, for example, after a recent blood transfusion.

It is hardly possible to use the term “reduced RDW value” when calculating the width of the distribution of erythrocytes, since this option reflects, as it were, the norm, and therefore cannot be taken as a laboratory indicator characterizing some phenomenon unusual for these blood elements. The less unnatural forms (due to an increase or decrease in volume) of erythrocytes in the blood, the more representatives of the population for this trait are within the normal digital values. And yet, if this happens (RDW - lowered), then, most likely, the analyzer made a mistake, and in order to correct this oversight, 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 distribution of red blood cells by volume is not increased, and clinical manifestations and laboratory tests confirm the presence of the disease (anemia).

Increased RDW

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

Megaloblastic and macrocytic, a typical representative is B12 / folic / -deficiency anemia. In the blood test: hyperchromia, the average volume of Er is above 160 fl, the cell diameter is more than 12 μm, RDW is increased (anisocytosis), different forms of erythrocytes (poikilocytosis);
Normocytic: aplastic anemia, as well as anemia caused by chronic pathology (tuberculosis, pyelonephritis, collagenoses, liver disease), a 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, the diagnosis also relies on another erythrocyte index - MCV, which characterizes a 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 in order to calculate the values of erythrocyte indices (including RDW), it is very important to compare the results obtained with the histogram of erythrocytes, which, after completing their work, is usually issued by modern hematological systems with software.

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

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

Obviously, for a certain range of pathological conditions, the calculation of 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 the laboratory service, the degree of anisocytosis was determined visually, when viewing a smear using optical equipment. And the distribution width of erythrocytes was not called RDW and was not calculated by a device designed for automatic hematological analysis. The calculation was carried out by a different method - using the Price-Jones curve, which, as it turned out later, did not coincide with the erythrocytometric curves performed by the “smart” machine with maximum accuracy, but it took a lot of effort and time for doctors and laboratory assistants to conduct the study. Now, having placed the sample in the "smart" apparatus, no one asks him one question - to work only on a separate test. The analyzer simply calculates everything that is provided for by the program and is embedded in it, so patients began to see new indicators, which were not even mentioned when processing samples manually.

And such studies were previously of interest mainly to hematologists to clarify the nature of anemia, who, if necessary, turned to the laboratory with a note in the direction: to conduct a morphological study of erythrocytes, calculate and present graphically (Price-Jones erythrocytometric 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, this indicator is likely to be of interest to a separate circle of specialists. Well, if RDW is present in the blood test, then patients have the right to ask questions.

Currently, an automatic hematology analyzer successfully copes with the calculation of RDW in a blood test, which quietly, quickly and efficiently solves the problem. And makes RDW everyone.

Reasons for increasing and decreasing the width of the distribution of erythrocytes by volume

As you know, blood is formed not only by liquid (plasma), but also by various cellular elements, such as erythrocytes, leukocytes and platelets. All of them must have a certain size, volume (cv) and shape for normal functioning.

Any change in these parameters affects the usefulness and functional activity of cells, which can lead to various disorders of homeostasis. It was in order to be able to evaluate these cells that a special index was created - the distribution width of erythrocytes (RDW).

What does indicator mean?

This term is understood as an index that allows you to get an idea of the distribution of cells of various sizes or shapes in the blood. Simply put, the width of the distribution of red blood cells provides information about what percentage of red blood cells in the blood, the size or volume of which is reduced or, conversely, more than necessary. Usually, it is used to evaluate the form, however, there is also its version for evaluation by volume - RDW-CV.

As you know, in order to supply oxygen to every cell of the body, an erythrocyte must pass even into the smallest vessels. That is why, physiologically, in size and size, the cells must correspond to the lumen of the vessels. If too large or, conversely, too small cells appear in the blood, this leads to the development of various disorders at the cellular and subcellular levels. As a result, it becomes necessary to determine the cellular composition of the blood using the RDW-CV indicator.

The distribution index of erythrocytes by volume in an adult is from 11 to 14.5%.

It is with this ratio of “atypical” cells that adequate blood supply to internal organs and tissues is still achieved. Reducing it below normal negatively affects the condition of the cells. In children, the norm of this indicator is slightly higher and can be up to 20%.

In addition to determining their volume, the calculation of the standard deviation (SD) is also shown. It quantifies the difference between the largest and smallest cell in an assay (usually referred to as RDW SD in assays).

Given all the variability and possible subsequent violations, it is necessary to understand in which cases an increase in RDW occurs, and when this index is lower than necessary.

Reasons for increasing the width of the distribution

The width of the distribution of erythrocytes is increased when the percentage ratio between small and large erythrocytes increases towards larger cells. Due to the redistribution of hemoglobin, which is the main molecule of red blood cells, less of them are synthesized in the body, which leads to the development of anemia, as well as anisocytosis, a condition in which most of the red blood cells differ from each other.

A characteristic feature of such cells, as mentioned above, are excessively large sizes, as well as a lifespan below the physiologically programmed. As a result, during their mass death (apoptosis in the spleen), a large amount of bilirubin is released, which negatively affects the state of the liver and other internal organs.

The distribution of red blood cells by volume may be higher than normal as a result of:

lack of iron, folic acid and some B vitamins. It is a fairly common cause of anisocytosis, which leads to an increase in the width of the red blood cell distribution.
oncological diseases. The most common cause of the formation of red blood cells in the blood, differing in size and volume. Usually affects other hematopoietic sprouts.
heavy metal poisoning. Most often, the width of the distribution of erythrocytes changes with lead intoxication of the body.

All of these causes require competent and qualified treatment. Otherwise, all of them can cause significant harm to the body, even death.

Reasons for the decline

If a patient's RDW-CV is below normal, then all blood cells are the same size (i.e., there is no significant difference in cell volume).

If the distribution width of erythrocytes by volume is reduced, the most likely diagnosis is microcytosis, in which all formed erythrocytes are small and cannot adequately supply tissues with oxygen.

Thalassemia is one of the most common diseases accompanied by the synthesis of small erythrocytes and, accordingly, a decrease in the RDW norm. This disease is hereditary, and manifests itself as a violation of the synthesis of normal hemoglobin chains, the activity of which in relation to oxygen is lower. At the same time, the blood loses its ability to normal and adequate exchange of gases (the index of the ratio of oxygen and carbon dioxide is lowered), which as a result leads to a violation of the functions of internal organs.

Characteristic of this disease is a change in the morphological properties of erythrocytes with a decrease in their size, as well as the appearance of "target" erythrocytes, the activity of which is reduced. Clinically, the disease is characterized by a deformity of the skull, an increase in internal organs (especially the liver and spleen), as well as the appearance of icteric skin color.

Another, no less common disease, in which RDW becomes below normal, is the development of microspherocytosis. This disease is hereditary, and its relative frequency of occurrence does not exceed a tenth of a percent.

With its development, an increase in the number of small and spherical erythrocytes in the patient's blood is observed, and the RDW index is lower due to their short lifespan. At the same time, due to the inferiority of their membrane, the current of sodium ions inside the cell increases, which leads to intravascular death of erythrocytes and the development of hemolysis. Clinically, this is manifested by the development of a feeling of weakness, anemia, jaundice and disruption of the internal organs.

If the patient has any of these symptoms, then it is necessary to conduct a comprehensive examination of the whole organism as soon as possible.

What does it mean if the distribution index of erythrocytes is lowered

The distribution index of erythrocytes is lowered - what does this mean? An important indicator of the general blood test is - RDW. It allows you to determine the volume, shape and size of red blood cells. Blood cells are responsible for the distribution of oxygen throughout the body, and also remove carbon dioxide and toxins. If rdw is reduced, this indicates a pathological deviation of the organ or system.

Therefore, it is important to understand what to do when the erythrocyte distribution index is low, and what this means for health. Some diseases can be diagnosed using the RDW index.

What is RDW?

Blood is based on cells that are produced by the bone marrow. There are three types of cells: blood, white and red bodies. It is red cells that are called erythrocytes, their condition is determined using a blood test.

In healthy people, the cells are the same in volume, shape and color. The analysis indicator may fluctuate slightly, experts call this coefficient - the width of the distribution of erythrocytes by volume.

There are two types of this indicator:

rdw cv, shows the distribution of erythrocytes by volume as a percentage;
rdw sd - allows you to evaluate the degree of deviation.

A pathological abnormality in the size of red blood cells is called anisocytosis.

A blood test is carried out with a special apparatus, the coefficient is determined as a percentage. The normal RDW in adults ranges from 11 to 15%, any deviation indicates a pathological process in the body. An increased index means that red blood cells differ in size, their vital activity is reduced. If the indicator of the distribution of erythrocytes by volume is lowered, more often this indicates anemia of varying degrees.

Only an experienced doctor can correctly decipher the blood test, establish the cause of the disease. In case of violations of the norm, the patient is recommended an additional study, which will determine the cause of the disease.

A reduced result is very rare and more often the patient is sent for re-blood sampling. After all, a hematological device can only show a high or normal level.

Such a blood test is often prescribed at the first stage of diagnosis in conjunction with other indicators.

Blood sampling is carried out when the patient is placed in a medical facility or before surgery.

And also a blood test is regularly carried out to assess the patient's condition in dynamics in order to determine the effectiveness of treatment.

Blood sampling is carried out in the morning, from 8 to 11 o'clock, before the manipulation, you can not eat food, coffee, tea, cigarettes. After the last meal, at least ten hours should pass. Do not be nervous before the procedure.

Taking a blood sample, the specialist places it in a centrifuge, this will separate the liquid from the cells. Then the resulting sample is placed in the analyzer, where the equipment independently counts the cells, their condition and issues a conclusion.

The doctor receives the result in the form of a histogram. If the result is positive, the manipulation must be repeated to exclude a false indicator.

Causes and signs of low RDW

A low erythrocyte distribution index coefficient can be observed for the following reasons:

Too much blood loss due to injuries or other pathologies. Particularly dangerous is uterine or gastric internal blood loss. In such cases, there is little chance of saving a sick person.
Surgery to remove an organ.
Metabolic disorders, undigested food begins to ferment in the stomach, which causes putrefaction.
Hormonal failure, more often observed in women.
Deficiency of vitamins, iron.
Pathological blood diseases in which red blood cells lose their biological function.

If a person has a low RBC distribution index, then characteristic symptoms of anemia appear:

the patient constantly feels lethargy, quickly gets tired without physical exertion;
dizziness;
constant fatigue, decreased performance;
shortness of breath, dry cough;
high blood pressure;
cardiopalmus;

Such negative manifestations are observed due to a violation of the biological process. The blood cells become small and poorly carry oxygen throughout the body. First of all, the nervous system, which is responsible for impulses, suffers.

At the first ailments, it is necessary to consult a doctor. The specialist will prescribe a blood test, conduct an additional study, which will help prescribe adequate treatment.

Increased value of the indicator

More often, patients have an increased value of the width of the distribution of erythrocytes by volume. Such a deviation - anisocytosis, is not an independent disease, more often it is a sign of a pathological process.

With such a deviation, the spleen enlarges, which causes a violation of the functionality of other organs.

The main reasons for the increase in RDW:

serious liver problems;
lack of vitamins of groups A and B12 in the body;
deficiency of iron and folic acid;
malignant tumor;
alcohol abuse;
leukocytosis.

And also a pathological increase is observed in case of chemical poisoning, diseases of the cardiovascular system.

An increase in the RDW coefficient leads to a yellowish complexion due to disruption of the liver and spleen.

A person has a breakdown, fatigue, increased sweating. Due to disturbances in the nervous system, the patient's mood changes dramatically, the excited state is replaced by indifference and alienation.

Shortness of breath is observed, the heartbeat becomes more frequent, the color of the nails and eyeballs changes.

In order to troubleshoot problems, it is important to establish the cause of the deviation. In addition to drug treatment, it is necessary to adjust the diet, lifestyle.

If you follow all the prescriptions of doctors, you can normalize the state of red cells, their normal functioning. You need to take a complex of vitamins containing B12, folic acid, monitor hemoglobin.

How to prevent the problem?

The value of the indicator below the norm is extremely rare, and it is quite difficult to prevent it. It is important to regularly undergo preventive examinations, to monitor the general state of health. To avoid false blood test results, you must follow the doctor's recommendations.

But it is important to adhere to the elementary preventive rules that doctors advise:

eat properly and balanced, fresh vegetables and fruits should be present in the diet;
take walks in the fresh air;
lead an active life;
do gymnastics;
at the first symptoms of malaise, contact a medical institution.

Many serious diseases are hidden and do not manifest severe symptoms. Only with a complete study can a pathological deviation in the body be detected. Having determined the cause of the violation, the doctor will be able to correctly prescribe drug therapy. Self-medication will only aggravate the situation, often lost time leads to serious consequences.

How often do you need to check for RDW? And at what age should you start worrying about it? It's just that my mother has hepatitis C and I don't know if I need to check the RDW? And what is the most important thing to do from the above in order to avoid problems with RDW?

In what cases can a child of 11 years old have an unstable RDW? Is it worth sounding the alarm?

Quite an important indicator, according to the values of which one can judge the presence of a number of diseases. This analysis allows you to find out the state of red blood cells in the blood by their volume. The best option would be to have red blood cells of the same volume, since the volume (and not the size) of red blood cells depends on the efficiency of oxygen supply to tissues and organs.

However, due to various circumstances, erythrocytes can differ in volume from each other. So, in the results of a blood test, numbers are interesting that determine the presence of erythrocytes of various sizes and the difference between them.

Note that anisocytosis is an abnormal change in the size (volume) of red blood cells. If 7 - 7.5 micrometers is considered to be the norm, then macrocytes (large cells) with sizes from 8 to 12 micrometers are considered deviations. Small deviations from the norm are not critical. The ratio between normal and altered erythrocytes is considered to be the norm as 5:1.

Attention. Clinically, anisocytosis can manifest as anemia, heart failure, and shortness of breath.

And just RDW in the analysis shows the order of violation of the distribution of erythrocytes in size.

It should be emphasized that the percentage width of the distribution of erythrocytes includes two markers:

RDW-CV is an indicator of the number of cells of different volumes, i.e. the severity of such a manifestation as anisocytosis.
RDW-SD - using this indicator, the difference between the sizes of red blood cells is assessed - from the smallest to the most pronounced.

In what cases is the analysis carried out

Under ideal conditions, even in normal outpatient conditions, when taking blood for a general clinical analysis, such an indicator as RDW and MCV must be indicated. Unfortunately, this often does not happen, and these indicators can significantly help in the diagnosis and early detection of many diseases.

This study provides assistance in case of suspicion of:

Lack of iron, cyanocobalamin, folic acid in the body.
For the differential diagnosis of thalassemia from iron deficiency anemia.
Assessment of the state of the body in oncological processes and pathology of the cardiovascular system.

The main symptoms to look out for and the doctor should order a blood test for RDW are:

Hyperthermic syndrome, especially prolonged. Without pronounced external signs of any disease.
Malaise.
Fatigue even after a good sleep.
Sweating day and night.
Drowsiness.
Unstable mood.
In some cases, the skin acquires a yellow tint.

How is the study going

For research in an adult, blood is taken from a vein on any arm. The analysis is carried out on an empty stomach. In young children, material can also be taken from a finger.

The result of the analysis is transformed into a histogram, according to which the results are evaluated. In the case of indicators within the normal range, the data are considered negative. If the manipulations revealed an increase in RDW, then the analysis is considered positive.

In some cases, the results of the study may be false positive, since the blood of a healthy person may contain red blood cells that have changed in shape and size. For this reason, it is recommended to use the Price-Jones curve in the process of interpreting the results.

Deciphering and meaning of the RDW indicator in the general blood test

For the correct interpretation of the obtained data, it is necessary to take into account the MCV indicators. The main goal in this case is the difference between the types of microcytic anemias.

RDW indicators in a blood test are the most important characteristic of the state of red blood cells. The ratio between red blood cells of different sizes in the blood can indicate a large number of diseases up to the development of malignant neoplasms.

To adequately characterize the indicators, it must be remembered that the RDW index can change rapidly, since it is not a constant value.

In general, in any study of a general blood test, the RDW index is to be calculated, since it is he who will fully characterize the state of the whole organism as a whole.

When determining the overestimated indices of the index, it is necessary to prescribe additional examinations, based on the main pathology of the patient.

In the case of elevated rates, it is necessary to look for more serious causes in order to determine the development of formidable diseases at the very beginning of their development.

Relationship with MCV

With a change in the RDW-CV in the blood, an increase in the MCV will be observed.

Unlike CV, RDW-SD is independent of MCV levels.

An analysis of such indicators as RDW and MCV allows for a qualitative analysis of the state of the blood, as well as the nature of the pathological process, but which the blood gave a reaction.

Norm RDW

The indicators of a healthy person are as follows:

Adults - from 11.5 to 14.5%.
Children under 6 months - from 14.9 to 18.7%.
Children older than 6 months - from 11.6 to 14.8%.

Reduced and elevated levels

The situation in which the RDW is elevated, that is, we have more red blood cells than we need, is quite dangerous. The fact is that one of the main disadvantages of macrocytes is their shortened lifetime. In itself, this is bad, because you need to somehow maintain the total number of red blood cells in the norm.

But more importantly, the number of simultaneously decaying red cells increases and, as a result, the flow of released iron and bilirubin increases. This increased flow begins to load the liver, which is now overworked.

In addition, some of the macrocytes in their diameter are not able to squeeze through the diameter of the capillaries, and the spleen is connected to their utilization. The load on it leads to its increase in size, and the spleen begins to put pressure on the intestines and stomach. Surrounding tissues and organs may be affected.

An increase in RDW values of more than 15% indicates the development of pathological conditions in the body. Most often, RDW is elevated when:

The combination with high MCV rates with increased RDW is liver damage with alcoholism, hemolytic anemia, megaloblastic anemia, vitamin A hypovitaminosis.
Combination with low MCV with elevated RDW - low hemoglobin, iron deficiency, the most initial manifestations of thalassemia.
Combination with normal MCV values with elevated RDW is a manifestation of iron deficiency anemia, a decrease in vitamin B12 and / or folic acid, which leads to macrocytic anemia.

A decrease in RDW below 10.2% occurs in the presence of the following pathological processes in the body:

With normal RDW, accompanied by a decrease in MCV, they talk about:

Frequent blood transfusions, in which there is a dissociation in the formation and presence of blood cells.
Severe thalassemia.
Hemorrhagic processes due to chronic blood loss, to which the human body does not react at the onset of the disease with any external manifestations.
Removal of the spleen due to traumatic injuries - in this case, there is a sharp redistribution of blood cells, as well as a delay in the formation of blood elements due to the absence of one of the important organs of hematopoiesis.
Malignant neoplasms in which inhibition of cell growth of the blood system occurs.
Conducted chemotherapy, where, as in the course of chemotherapeutic treatment, suppression of the cellular elements of the blood system is observed.
development of myelodysplasia.

Important! Very often, the debut of various diseases is missed due to insufficient diagnosis.

A timely, complete, and most importantly competent study, first of all, of blood parameters will tell the doctor about many changes in the human body. This will not allow you to miss the onset of many diseases, even such as malignant neoplasms of various localization.

The constancy of homeostasis determines the normal existence of any living organism. This also applies to the human body, in which any metabolic disturbance leads to the development of various diseases or pathological processes. This is especially true for erythrocytes.

Normally, all erythrocytes have relatively the same size and shape, however, in some diseases, an increase in the number of cells with a different volume or size may occur, that is, they are distributed according to their qualitative characteristics. It was for the evaluation of such cells that a special index, RDW, was created.

What is this indicator and what are the reasons for its change? What does distribution width mean and how is it decoded?

What is RDW and its varieties (CV and SD)

The RDW in a blood test is an average value showing by volume. Its norm is from 11 to 15%, that is, in the blood of a healthy person, the presence of such a number of red cells that differ from standard ones is permissible.

The RDW in a child may be slightly less than in an adult due to the presence of fetal hemoglobin, which leads to the appearance of physiological anisocytosis. In men and women, the levels of width are the same, although, in some cases, there may be a pronounced variation in the limits of the norm.

There are two types of this indicator - RDW-CV, showing the percentage distribution of erythrocytes by volume, and RDW-SD, which shows their standard deviation.

RDW-SD is measured in femtoliters and shows the difference in volume between the largest and smallest RBCs detected. In women, it is characterized by relative constancy, while in men, some deviations are possible due to bad habits, more frequent incidence of lung cancer, and so on.

It should be noted that there is always a direct relationship between this index and another erythrocyte index - MCV (mean erythrocyte volume), and it is by their ratio that one or another disease can be diagnosed.

Ratio of MCV and RDW

The RDW-CV index is directly dependent on the MCV level. Its definition is carried out by dividing the product of the standard deviation of erythrocytes and 100%, divided by the average volume of erythrocytes. Thus, the larger the average red cell volume, the larger the RDW-CV value.

This indicator is quite important in the diagnosis of various hematological diseases. With its help, it is possible to detect the presence of anemia or other pathology of the blood system. To determine RDW and MCV, an extended complete blood count is taken, which is prescribed when the attending physician suspects a patient has a disease or a change in the distribution of his blood cells by volume.

Analysis interpretation: RDW increased

The reasons that can lead to the fact that RDW in a blood test is elevated are quite different.

The norm, as already mentioned, is from 11 to 15%. The index rises as a result of the appearance in the blood of erythrocytes that do not correspond to normal sizes, that is, with the appearance of anisocytosis. If the indicator is increased, then its deviation can be caused by the following reasons:

Pathology of the bone marrow. Various processes, such as myelodysplasia, cancer, heavy metal poisoning, can lead to changes in bone marrow activity and the synthesis of “non-standard” red blood cells. It is these diseases that most often lead to an increase in the width of the distribution of erythrocytes. Sometimes, despite the oncological process, a normal number of red cells can be observed with a significant separation according to other morphological features.
Folic acid deficiency provokes the development of folic acid deficiency anemia, which leads to the formation of a large number of macrocytes. As a result, the RDW rate deviates upwards and the width of the distribution changes. Normalization of the amount of this vitamin contributes to the fact that the rate of the indicator is restored. In women, this condition occurs during pregnancy, which is why doctors recommend taking folic acid during pregnancy.
Hemoglobinopathies- diseases associated with a violation of the structure of hemoglobin produced, for example, with sickle cell anemia. As a result of their development, the formation of blood cells of a larger volume occurs. Due to the inferiority of hemoglobin, the transport function of the blood suffers, which leads to an increase in HB in the cell. Accordingly, the width of the distribution increases significantly.

All of these conditions lead to the fact that the RDW indicator increases, the distribution of erythrocytes by volume changes, which negatively affects the state of the body and internal organs.

Reasons for the decline

When the RDW in a blood test is lowered, does it mean a decrease?

If the norm shifts down, it means that most of the erythrocytes in the blood are of the same size, that is, they are not distributed by volume and size.

Such a change can be observed either with a decrease in the number of cells with an increase in their size (it can be observed in women with the appearance of fetal hemoglobin in their blood), or, conversely, with the synthesis of a huge number of small red blood cells (the distribution width is close to zero). A decrease is extremely rare, and usually requires clarification of the status of other indices.

More often than not, if the RDW width does not match the decrease in MCV, then there is a diagnostic error, which is often observed when performing manual cell counts. In this case, it is recommended to repeat the study, and if the level is again lowered, then the doctor should begin to identify the reasons for the deviation of the indicator from the norm.

If the width of the distribution of erythrocytes is increased. RDW in a blood test - what is it

Decrease in RDW: pathology and norm

Why is RDW needed?

How is it determined?

What do the results depend on?

Index variations

What do the low values ​​mean?

Causes

How is it manifested?

What to do?

Prevention

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Rdw in the blood test is lowered

What it is

Norm

Deciphering and meaning of the RDW indicator in the general blood test

RDW value

Clinical use

Relationship with MCV

Increased RDW

Normal RDW

What should be a normal RDW

Low RDW

High MCV

Liver disease

Hemolytic anemia

Megaloblastic anemia

Vitamin A deficiency

Low MCV

Decreased hemoglobin level

Intermediate form of thalassemia

Normal MCV

What does a blood test for RDW mean?

What it is

Norm

Why is an analysis ordered?

Relegation and promotion

How to prepare

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The distribution index of erythrocytes is lowered: what does it mean and what to do? Decrease in RDW: pathology and norm

Reduced RDW: norm and pathology

What does RDW mean in a blood test?

Why is it necessary to do an analysis on RDW?

How is it calculated?

Normal performance

Raise RDW

What do low scores mean?

Causes

What measures to take?

Preventive measures

How is it calculated?

Normal performance

Raise RDW

What do low scores mean?

Causes

What measures to take?

Preventive measures

Reduced RDW: norm and pathology

What does RDW mean in a blood test?

Why is it necessary to do an analysis on RDW?

How is it calculated?

Normal performance

Raise RDW

What do low scores mean?

Causes

What measures to take?

Preventive measures

The distribution width of erythrocytes (RDW index): what is it, the norm, increased and decreased

Distribution of erythrocytes by volume

Is it always possible to believe the norm?

Increased RDW

Why is RDW a new indicator for patients?

Reasons for increasing and decreasing the width of the distribution of erythrocytes by volume

What does indicator mean?

Reasons for increasing the width of the distribution

Reasons for the decline

What do the low values mean?