Category: blood test Published 08/02/2018 · Comments: Comments on the entry PDW in a blood test are disabled · Reading time: 6 min · Views: - 1,452
Analysis of blood components has been and remains the simplest and most widely available way to determine whether there are any abnormalities. Despite the fact that this method is very simple, it is quite informative.
And therefore, when making a diagnosis, doctors often refer patients for analysis. Why is the examination so informative and can help detect various diseases at an early stage?
Platelets and pdw
It is worth noting that pdw blood test is the width of broken platelets by volume. In other words, it is an index of platelet element distribution. The size of these particles ranges from 2 to 5 micrometers. According to their characteristics, platelet particles are blood plates. This name is explained, first of all, by their flat, protruding, oval shape. They do not have a core and a specific color.
The functional operation of these components is explained as follows:
- promote the release of factors that are involved in blood clotting. This process is necessary for the formation of blood clots in those places where the integrity of the tissues is compromised,
- The functional work of platelets is to supply immune complexes to those areas where there is an inflammatory process. They help eliminate it quickly
- produce growth factors. Their functional ability is to restore the walls of the vessel, providing them with nutrition. They supply biologically active components to the area of the vascular walls,
- provide a filtration process from antigens.
It is worth noting that the synthesis process occurs in the bone marrow. About 80% of their number is in the blood, 20% is attributed to the spleen. In the liver area, transparent cells are recycled. The lifespan of platelet elements is about a week to two weeks.
The process of formation and elimination of these particles occurs constantly, without interruption. In addition, individual cells can be identified that are at different stages.
We can distinguish several main stages of life activity of flat, nuclear-free bodies:
- initial stage of development,
- element maturity phase,
- gradual aging,
- stage where particle irritation is observed,
- liquidation stage.
Cell volume depends largely on the stage. As cells age, their volume becomes smaller. The pdw index shows the width over which platelets are distributed throughout the blood. By deciphering it, it becomes possible to decipher platelet heterogeneity.
Important! When assessing a blood test, the specialist evaluates the overall changes in the main indicators.
If the formed cells are stable in terms of indicators, then a slight deviation of platelets is not critical. MPV is carried out along with this analysis. Its value indicates the average volume of nuclear-free particles.
Reasons for RDW deviation
If the width of the distribution of red blood cells in the body is increased, this means that the sizes of the red blood cells are very different from each other. Moreover, the larger the red blood cell, the shorter its lifespan, which reduces the number of red blood cells in the body.
With significant destruction of red blood cells, an increased iron content is observed in the blood. At the same time, an increase in bilirubin occurs (the so-called very toxic substance that is formed from dead red blood cells). It is sent to the liver for neutralization, which causes it to become overloaded and poorly cope with processing toxins. This negatively affects the functioning of the entire body.
In addition, this situation negatively affects the spleen. In this organ, obsolete or destroyed red blood cells mainly die. Increased destruction of red blood cells causes the spleen to increase in size.
An increased RDW value in many cases indicates iron deficiency anemia. With this disease, the RDW value may increase even before the red blood cell and hemoglobin values change. That is why the volume of red blood cells makes it possible to determine the presence of the disease at the initial stage and take timely measures to eliminate it. At the same time, during treatment, the RDW index steadily increases, which is associated with the appearance of young red blood cells. If therapy is effective, red blood cell volume is the last indicator that returns to normal, and therefore indicates recovery.
In addition, the width of the distribution of red blood cells can increase in the following situations:
- Hemolytic anemia of an immune nature.
- Megaloblastic anemia (B9 and B12 deficiency).
- Hemoglobinopathy is the presence of pathological hemoglobins in red blood cells and is inherited.
- Liver problems.
- Blood transfusion.
The width of the distribution of red blood cells is never considered by a doctor separately from other indicators. The doctor must look at other erythrocyte indices (MCV, MCH, MCHC). This is necessary in order to more accurately diagnose a person’s condition.
For example, if the value of the distribution width of erythrocytes is within the normal range, while the mean erythrocyte volume (MCV) is reduced, this may indicate a hereditary disease that is associated with a violation of the synthesis of one of the globin chains (thalassemia). The MCV value is lower than normal and the RDW content can be normal during hemorrhage, when the walls of the vessels are so permeable that blood leaks through them, leading to hemorrhages. In addition, normal erythrocyte volume and low average erythrocyte volume are observed after removal of the spleen in oncology.
It may also be that the width of the distribution of red blood cells is increased, while the average volume of red blood cells is decreased. Then you can suspect iron deficiency anemia or beta thalassemia (a disorder of the synthesis of the beta globulin chain). If both values are high, the body may be deficient in vitamin B or develop hemolytic anemia.
Normal value
At the maturity stage, a predominant number of platelets is observed. During this period, they demonstrate to a greater extent their functional blood clotting ability. The deviation of the main parameters should not exceed or decrease by 10% value. If the value exceeds the norm, this threatens the formation of blood clots. Over time, this process contributes to blockage of blood vessels. When the indicator decreases, blood loss is observed.
The width of particles in the body of a healthy person before reaching the age of eighteen becomes 10 - 15%. The normal value for an adult is 15–17%. If there is a deviation from these parameters, the specialist considers the likelihood of disruption of the normal functioning of individual organs and systems. This process may indicate the development of inflammation, or pathology, in the human body.
Increase pdw
If the value of the indicator exceeds the permissible value, then this indicates heterogeneity in the volume of platelet particles. This situation has a detrimental effect on the human body and provokes the development of a pathological process. Gradually, as a result, the vessels and capillaries become clogged. Blood circulation is disrupted, as a result of which metabolic processes slow down, and heart attacks are possible in the future.
An increase in platelets may occur in certain cases:
- when diagnosing anemia. This process provokes oxygen starvation, due to which the particles change their volume,
- a high level of concentration of non-nuclear particles is observed in cases where there is bleeding after surgery or certain injuries,
- when neoplasms occur. Such pathological changes contribute to damage to the formed components of the blood. Due to this process, platelets in the blood volume change their normal values,
- The value of platelets increases in the presence of inflammatory processes in the body. Their width is distributed throughout the volume. If this clinical picture is accompanied by an increase in leukocytes, the specialist will diagnose inflammation.
Attention! An increase in the index does not guarantee that an inflammatory process is occurring in the human body.
In the event that the patient does not comply with the recommendations before taking the test, it is possible to change the basic parameters. It is worth remembering that blood sampling occurs in the morning, on an empty stomach. The last meal should be taken 12 hours before the test. Also, doctors recommend not to engage in excessive physical activity; on the eve of the study, emotional and stressful situations should be avoided. In addition, you should avoid taking medications and vitamins if possible.
Analysis procedure
How to donate blood for analysis
A general blood test is convenient because you can take it without problems and at almost any time (if we talk about paid laboratories). However, the analysis is influenced by many factors: food intake, medications. For this reason, doctors always recommend donating blood in the morning, before meals. If you cannot come in the morning, it is important that at least 8 hours have passed since your last meal, otherwise the test results will be distorted.
Most often, capillary blood is taken, that is, from a finger. In some cases, venous blood is needed from a vein in the bend of the elbow (in infants, it is taken from a vein in the head or under the collarbone).
The fact is that the volume of blood from a vein is much greater than what can be taken from a finger. This means that for determining some indicators, the results will be more accurate and true.
You won’t have to retake them later or look for another laboratory. For older children, it is easier to draw blood from a fingerstick because it is faster and easier for the nurse. In addition, children are often frightened when they see a large amount of blood in a syringe. Before donating blood from a vein, you may be asked to sit in the waiting room for 10-15 minutes. This is not done for the sake of formality. The patient rushing for analysis is in an excited state, this can affect the result and reliability of the analysis.
Once the nurse draws your blood, she will immediately send it to the laboratory for testing. Usually you need to wait 2 days for the result. In paid laboratories they can do it faster, in a day. Often a blood test is the main method for determining pathology, so it is extremely important that it is accurate. For this purpose, the patient has the right to contact several laboratories at once, and donate blood to 2 or 3 laboratories at once. When the doctor has all the results, he will be able to more accurately diagnose and prescribe treatment.
Useful information about what red blood cells, white blood cells and platelets are.
Read: What CHOL says in a biochemical blood test
The patient receives the test results, which indicate the norm and deviation from it in all indicators. If you did the analysis in a paid laboratory, they can send the result by email, it will indicate not only the number of your indicator, but also the norm next to it so that you can compare them. The doctor will decipher and explain in detail. You need to look at all indicators as a whole; a deviation in PDW alone cannot mean this or that disease. You should never self-diagnose yourself based solely on the results of a blood test. They provide only 60-80% of all information about the state of the body.
Decrease pdw
The pdw index is lowered if flat blood cells are in small quantities. Just as in the previous case, deviation is not always a pathology. During critical days, women experience a decreased platelet count. Among the reasons for deviation to the smaller side are an individual’s incorrect lifestyle, physiological characteristics, or an unbalanced diet.
In addition to these cases, the following situations are distinguished:
- the presence of neoplasms,
- development of pathological changes in the area of blood formation,
- in case of dysfunction of the liver, in case of anemia,
- in case of taking cytostatics.
A low platelet count is just as dangerous as an elevated platelet count. If there is a slight decrease, this situation should not be neglected. It is important to maintain the clear cell count at an optimal level.
Important! By following simple recommendations, the indicators during a blood test will be optimal, and the human body will not experience discomfort.
