Hematocrit is the proportion (in percent) of erythrocytes from the volume of blood (total). This indicator reflects the ratio of the volume of plasma and the volume of erythrocytes. For example, in a patient who is in a state of shock, a decrease in hematocrit may not occur, while as a result of blood loss, the number of red blood cells in general may decrease. Therefore, the percentage can not be used, assessing the degree of anemia in the near future after blood transfusion or blood loss.
Hematocrit may also be lower if the patient is lying down while taking the analysis. With prolonged compression of the vein harness, a false positive result can be observed. A falsely low hematocrit may also be due to blood thinning. This happens when the blood for analysis is taken from the same limb, into which there was absolutely immediately before this intravenous infusion.
For example, there is a blood test with a lowered hemoglobin. It should be noted that this indicator can be due to various reasons. As factors, iron deficiency anemia, as well as anemia associated with latent bleeding or elevated hemolysis, can act. Having conducted additional studies, it can be revealed that the cause of anemia can be the loss of red blood cells, and its consequence, respectively, is a reduced hematocrit. Having determined the color index, they reveal violations in the synthesis of hemoglobin itself. This allows you to determine what kind of anemia is: hyperchromic, hypochromic or normochromic.
Hematocrit lowered is typical for anemia, which is caused by a decrease in the number of red blood cells. These conditions are associated, as a rule, with hemolysis or blood loss. Hematocrit may also be lower in conditions that trigger an increase in the volume of circulating blood. This is noted during pregnancy, hyperalbumia, or when eating salt in large quantities.
The color index may decrease with decreasing hemoglobin synthesis. This leads to a decrease in the concentration of hemoglobin in erythrocytes. Reduction of the color index is also characteristic for the state in which the size of erythrocytes (microcytosis) decreases. An increase in the color index is noted in macrocytosis. In this case the erythrocyte increases and contains more hemoglobin. This phenomenon is observed with folic anemia, hypothyroidism, cytotoxic therapy.