Red blood cells, one of the tangible components of the blood, are usually kept at a relatively constant level. A low red blood cell count indicates the presence of certain factors in the body that affect the stability of red blood cells. For example, a large amount of water, a large amount of fluids, or a relatively low level of red blood cells produced by mothers and lactating women due to increased loss of body fluids as a result of childbirth and breastfeeding. These physiological factors usually do not require specific treatment and the cell count can gradually return to normal levels. The loss of erythrocytes for various reasons, the reduction of erythropoiesis or increased destruction of erythrocytes, will produce a number of diseases or symptoms that adversely affect the human body and require timely treatment, if necessary, intravenous blood transfusion. 1, excessive loss of red blood cells: such as trauma, surgery, acute and chronic blood loss in the body may be due to excessive loss of red blood cells in the body resulting in low red blood cell count, the need to stop bleeding in a timely manner. Such as trauma caused by the wound should be treated as soon as possible and stop bleeding. If the wound is caused by surgery, the blood should be drained from the wound in time to avoid the formation of hematoma and compression of local tissues, and then treated according to the cause of bleeding. In addition, taking rifampin, birth control pills, etc. may also lead to the loss of red blood cells, according to the doctor’s advice to decide whether to stop the drug; 2, erythropoiesis: such as aplastic anemia, iron deficiency anemia, megaloblastic anemia, leukemia, sepsis, myelofibrosarcoma, etc., mainly because of the lack of hematopoietic raw materials or utilization disorders in the hematopoietic process, can lead to a reduction in the production of red blood cells, laboratory tests 3.Increased destruction of red blood cells: such as immune system diseases, malaria, burns and other causes of hemolytic anemia, thalassemia, etc., due to excessive destruction of red blood cells and resulting in low red blood cell counts, while actively improving the state of anemia, but also to give targeted treatment of the original disease. 4, lack of hematopoietic substances and utilization disorders: such as iron deficiency anemia caused by iron deficiency, megaloblastic anemia caused by folic acid and vitamin B12 deficiency. Iron deficiency anemia requires active iron supplementation, while megaloblastic anemia requires vitamin B12, folic acid, etc., depending on the situation. Most of the clinical examination findings of erythrocytopenia are suspected to be anemia, but the effect of other diseases should still be considered and further tests are needed to clarify the cause and take targeted measures.