Crying too much does not cause anemia, but it can cause a person to be moody, mentally upset and anxious. The causes of anemia are insufficient or reduced red blood cell production, excessive red blood cell destruction and blood loss. 1. Insufficient or reduced erythropoiesis: aplastic anemia due to bone marrow failure, megaloblastic anemia due to folic acid or vitamin B12 deficiency, iron deficiency anemia due to iron deficiency, and abnormal bone marrow hematopoiesis due to malignant blood diseases, such as acute leukemia, which can cause insufficient or reduced erythropoiesis. 2. Excessive destruction of red blood cells: the shortened life span of red blood cells is called hemolytic anemia. Some intrinsic defects of red blood cells or external chemical poisons, drugs, microbial infections can lead to hemolytic anemia, such as paroxysmal sleep hemoglobinuria. 3. Blood loss: Chronic blood loss is the most common cause of anemia, such as blood loss from ulcer disease and blood loss from tumor rupture. If the diagnosis of anemia is confirmed, it is recommended to carry out standardized treatment under the guidance of physicians as early as possible in order to reduce the adverse effects of the disease.