Low erythrocyte volume, there are generally two situations: first, after a large number of infusions and a large amount of water, due to the increase in plasma volume, the concentration of red blood cells decreased caused by low erythrocyte volume, if too much water out of the body, low erythrocyte volume will be corrected, this situation does not require special treatment. Secondly, the most common cause of low red blood cell volume is anemia, and there can be various types of anemia in clinical practice. The common ones are iron deficiency anemia, aplastic anemia, hemolytic anemia, thalassemia and so on. All of these anemias can cause low red blood cell volume. Their treatment should be tailored to each type of anemia. For example, iron deficiency anemia requires iron supplementation and vitamin C supplementation. Thalassemia can be treated with blood transfusion or spleen excision. For aplastic anemia, cyclosporine and Conradron are needed. For autoimmune hemolytic anemia, prednisone acetate, dexamethasone and other medications are needed.