The normal value of human red blood cells is (4.0-5.5) × 1012/L for adult males and (3.5-5.0) × 1012/L for adult females. When the red blood cell count is consistently lower than this normal value, it is called erythrocytopenia. The causes of erythrocyte reduction include the following: First, physiological reduction: infants and children under 15 years of age, erythrocytes are generally 10% to 20% lower than normal adults; some elderly people, mid and late pregnancy can have erythrocyte reduction.
Second, pathological decrease: seen in all kinds of anemia. According to the different etiology and pathogenesis of anemia, anemia can be divided into: 1. Red blood cell production reduction: Red blood cell production mainly depends on three factors: hematopoietic cells, hematopoietic regulation, and hematopoietic materials, and any one of these factors can lead to a reduction in red blood cell production. For example: aplastic anemia, anemia due to lymphocyte hyperfunction, iron deficiency anemia, etc.
2, increased red blood cell destruction: that is, hemolytic anemia, such as hereditary spherocytosis, thalassemia, etc.
3, excessive red blood cell loss: according to the cause of blood loss, it is divided into bleeding coagulopathies (such as idiopathic thrombocytopenic purpura, hemophilia and severe liver disease) and non-bleeding coagulopathies (such as trauma, tumor, tuberculosis peptic ulcer).
In addition, in the case of hemodilution due to some causes, the total number of red blood cells remains the same due to increased blood volume, and the relative decrease of red blood cells per unit of blood, but the ratio of various cells remains the same.
Therefore, low red blood cells may be caused by the above reasons, but the specific patient which cause of low red blood cells need to be combined with the patient’s medical history and related tests to confirm the diagnosis.