According to the World Health Organization, anemia is diagnosed according to the content of hemoglobin in human body. Hemoglobin is the main component of red blood cells, which consists of iron ions and pearl protein. It is also necessary to check the iron quadruple test, including serum iron, transferrin and unsaturated iron binding capacity, to confirm the diagnosis of iron deficiency anemia. Although iron deficiency anemia is relatively common, not all anemias are iron deficient. There are some chronic diseases that cause ischemia, such as chronic renal failure that causes decreased erythropoietin production, and the anemia can only be corrected by in vitro supplementation of erythropoietin.