Hematocrit, which is the volume of red blood cells in the peripheral blood as a percentage of the total blood volume, and the normal value of hematocrit are closely related to gender. The normal hematocrit is 40%-50% for adult males and 37%-48% for adult females. If it is lower than the normal range, it often indicates that the number of red blood cells in the body is reduced, which can be seen in various types of anemia, including anemia caused by erythropoietic disorders, anemia caused by the lack of erythropoietic raw materials, anemia caused by erythropoietic lysis and destruction of red blood cells, and the existence of the body’s chronic blood loss, which will be accompanied by a decrease in the hematocrit. Increased erythrocyte specific volume indicates that the number of erythrocytes in the body is increased, which is common in various chronic hypoxic diseases, which often cause the concentration of erythropoietin in the body to increase, stimulate the proliferation of erythrocytes, causing an increase in erythrocyte specific volume. In addition, myeloproliferative disorders such as true erythrocytosis and primary thrombocythemia also have a significantly higher hematocrit.