Low hemoglobin and erythrocyte hematocrit can be due to physiological factors in the middle and late stages of pregnancy, as well as to neoplastic lesions, autoimmune disorders, and hematologic disorders. Hemoglobin and erythrocyte pressure volume are indicators of anemia. Generally, when hemoglobin and erythrocyte pressure volume are low, physiological factors and pathological factors should be considered. 1. Physiological factors: it can be seen in the middle and late stages of pregnancy, which is related to the increase of blood volume and circulating blood volume of pregnant women, and the hemoglobin and erythrocyte hematocrit can be lowered, because it is a physiological state, so it is enough to monitor the blood routine regularly, and there is no need for special treatment. 2. Pathological factors: such as multiple myeloma, leukemia, lymphoma and other neoplastic lesions, as well as rheumatoid arthritis, lupus erythematosus, nodular histiocytosis and other autoimmune diseases; can also be seen in aplastic anemia and other hematologic diseases, in addition, massive blood loss can also cause low hemoglobin and erythrocyte pressure volume. Low hemoglobin and erythrocyte pressure volume alone cannot determine the cause accurately, but also need to be combined with the characteristics of the medical history and other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor.