The most common clinical observation is hemoglobin, which is 12-16 g/dL for men and 11-15 g/dL for women, and the number of red blood cells, which is also an indicator of anemia. The volume of red blood cells and the concentration of hemoglobin are two indicators that can initially determine which type of anemia is caused by large or small cells, such as folic acid or vitamin B12 deficiency, large red blood cells and anemia, plus the patient does not eat well and has a combination of stomach problems, the doctor can initially determine whether it is caused by malnutrition. In normal daily life, the most common is iron deficiency anemia, so iron supplements should be taken accordingly. In addition, there is another kind of anemia caused by blood loss, most often caused by excessive menstruation in some lesbians, which is often manifested as iron deficiency anemia.