In old age, all kinds of organs in the body are degenerated, and the hematopoietic system is no exception, so the elderly are often prone to anemia. Most anemia in the elderly is secondary to anemia, especially often secondary to malignant tumors, so the common anemia in the elderly are as follows: 1. Iron deficiency anemia: the most common in the elderly, accounting for about 33-66% of anemia, more in women than men. Most of the patients have reduced serum iron content, but the average hemoglobin concentration and average red blood cell volume are not low, so it cannot be explained by iron deficiency alone, and only 1/3 of the cases really need to be treated with iron, and 2/3 of the cases are accompanied by other lesions. In terms of pathogenesis, attention should first be paid to the presence of obvious or insidious chronic blood loss, often seen in peptic ulcers and gastric cancer, small intestinal tumors, or malignant transformation of gastric ulcers, atrophic gastritis, colon cancer, etc., which are very common in clinical practice. For women, attention should be paid to whether it is caused by gynecological tumors. In addition, hemorrhoids are also a common cause of blood loss. After the primary disease is detected, it should be treated actively and malignant tumors should be surgically removed in time. With the treatment of the primary disease, the anemia will also be improved. 2.Megaloblastic anemia: It is caused by vitamin B12 or folic acid deficiency. The gastrointestinal function of the elderly is weakened and the absorption function is also reduced, while the serum levels of folic acid and vitamin B12 in the elderly are low, so when the elderly are anemic, they should be treated with folic acid and vitamin B12 appropriately, and the possibility of malignant tumors of the digestive system should be actively excluded, otherwise it may lead to misdiagnosis and mistreatment. 3. Aplastic anemia: The bone marrow of the elderly is prone to mild aplastic dysplasia, and about 10-20% of reblasts occur in the elderly. It is important to distinguish aplastic anemia from myelofibrosis and anemia caused by malignant neoplasm in the elderly. If treated properly, patients can survive for many years, but most have a poor prognosis. In recent years, we have developed monoclonal antibodies to treat reoccurrence with satisfactory results in most patients. Therefore, anemia in the elderly should not be ignored, especially the occurrence of malignant tumors should be alerted, and comprehensive examination should be conducted to confirm the diagnosis and treatment in time.