The normal value of red blood cell count for adult male is (4.18-5.48)×10¹²/L; the normal value for adult female is (3.70-4.87)×10¹²/L. Low red blood cell count is mainly seen in physiological and pathological, and the causes of pathologically low red blood cell count are mainly seen in various types of anemia. 1. Physiological: Red blood cell counts in children under 15 years of age and infants are usually 10% to 20% lower than those in adults. In addition, some elderly people and pregnant women may also have low red blood cell counts. 2. Anemia: According to the cause of anemia, it is mainly divided into the decrease of red blood cell production, such as aplastic anemia, iron deficiency anemia, etc.; the increase of red blood cell destruction, which is common, such as hemolytic anemia, thalassemia, etc.; anemia caused by excessive loss of red blood cells, such as immune thrombocytopenia, hemophilia, peptic ulcer hemorrhage and so on. It can be seen that there are many reasons for low red blood cell count, do not judge or diagnose on your own based on the results of a test, you should consult a doctor in time, who will analyze and diagnose according to the specific situation.