The red blood cell distribution index is lowered: what does it mean and what to do? Decreased RDW: Pathology and Norm
Erythrocyte 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 toxins and carbon dioxide accumulated in the cells. In normal condition, 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 size of these cells vary significantly. Next, we will talk about the situations in which the index of red blood cell distribution decreases, how it manifests itself and what it shows.
Decreased RDW: norm and pathology
A person with good health has red blood cells of the same shape, density and color. In the case of a deviation, especially in the presence of autoimmune diseases or oncology, 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 function of the exchange in red blood cells is disturbed.
What does RDW mean in blood tests?
During the complete blood count, the red blood cell distribution index is determined. If you suspect the presence of a particular disease, 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 is so because these indices (by quantity and volume) are closely related to each other and help in determining the type of anemia.
It happens that the red cell distribution index is lowered. 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, but also the form is important.An increased distribution of red blood cells is observed in 1 out of 10,000 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 (planned) and as intended, if there are suspicions of any deviations in the blood charity function. The analysis is carried out necessarily before surgery, during pregnancy and in childhood.
Why do you need to do an analysis on RDW?
It was already mentioned above that the index of the distribution of red blood cells in the blood makes it possible to conduct a qualitative assessment of the composition of red blood cells, given their size.
But why do you need it? The thing is that these cells are very similar to each other, which gives them the opportunity to substitute each other or form blastula. Increasing cell size entails an increased need for nutrition and, in addition, this means that their lifespan is shortened. All this directly affects the overall indicator of red blood cells in the blood and the human condition.
With the death of a large number of red blood cells, iron is released and becomes more bilirubin, which has an increased load on the liver, and as a result it can not process these substances.
The RDW index is directly related to the pathological process, during which the red blood cell dimensions change (anisocytosis). This condition is a complex chemical process that causes all blood cells to suffer.
How is it calculated?
RDW is calculated as a percentage, the limit of which is considered to be the limit from 11.5 to 14.8. The distribution index of red blood cells is determined using a mathematical equation, which is the ratio of modified red blood cells and their total mass.
At present, computer labs are used in laboratories 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 change in the size of red blood cells.
The norms of the distribution index of red blood cells depend on gender, age and the presence of certain conditions that occur in the human body. For children under one year, the normal rate is 11.5-18.7%.At the age of one year and older, the values rush to the generally accepted rate of 11.5-14.5%.
For the female half of humanity, the upper limit is shifted to 15.5%, because their hormonal background changes 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 a person does not take any medications, as well as stay in a balanced internal state.
RDW levels are elevated in some situations. The most common cause of this pathology is iron deficiency anemia. The indicator can change at different stages of the development of pathology, which clearly reflects the histogram of red blood cells:
- The initial stage of development of anemia is characterized by normal indices, but hemoglobin will be greatly reduced. It is the result of the 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, such indicators as the average concentration and hemoglobin content in the blood cell and the average volume of red cells decrease.
In the treatment of IDA, it is necessary to normalize the level of iron-containing protein and its characteristics in human blood.
What do reduced rates mean?
Patients are often asked what this means: "the red blood cell distribution index is lowered." Since the red blood cell proliferation index cannot be estimated without a volume indicator, it is necessary to become familiar with all the options for underestimated indicators when they are related:
- RDW is lowered, and MCV is below average - indicating that there are problems with the spleen and liver.
- RDW is lowered, and MCV is above the normal level - it indicates the presence of cancer pathologies, mainly the development of metastasis in the bone marrow.
The fact that the red blood cell distribution index RDW sd is lowered, 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 taking blood;
- do not take any medication prior to analysis;
- refuse on the eve of the use of smoked and salty foods.
In the case when the red blood cell distribution index RDW sd is really lowered, which is necessarily confirmed by deviations from the norm of the MCV index, this indicates the occurrence of certain pathologies. These include:
- Hypochromic microcytic anemia - sometimes it is also called anemia. A condition in which red blood cells of irregular shape die because they have no biological value in the body.
- Malignant tumors - usually in this case we are talking about mastopathy, cancer of the bone marrow and lung.
- Hemolysis of red blood cells is a process during which red blood cells die before reaching their goal. As a result, active hemoglobin is released.
So, the red blood cell distribution index is lowered - what does this mean? There are several reasons that can reduce the rate of RDW:
- Acute blood loss with injuries and pathological bleeding.
- Frequent operations.
- A metabolic disorder during which consumed food 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 red blood cell distribution index is lowered?
A highly qualified doctor for consultation is likely to ask the patient to retake the analysis, because the RDW is almost never underestimated. Since this suggests that all cells are ideal in terms of their parameters, and this, in principle, cannot be. If the indicator was confirmed by repeated analysis, then conduct a full study of the state of the body, paying particular attention to oncological examinations.
You can prevent a reduced RDW figure with the following simple rules:
- The diet should be balanced, which includes a lot of fresh fruits, lean meat and vegetables.
- It is recommended to breathe fresh air as often as possible.
- An active lifestyle will help prevent a drop in the RDW index.
- It is very important not to miss the planned medical examinations, during which most often appear serious deviations from the norm, which 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 provides an opportunity to learn about their biological value. A decrease in RDW is very rare, but if the red cell distribution index is lowered, this means that there may be various pathologies.
The index is calculated based on the results of a general blood test, but it can only have full power in conjunction with the MCV indicator, since they are closely interrelated.