Anemia is usually seen in the hematology department, or in the gastroenterology or obstetrics and gynecology department if the patient has a history of blood loss such as gastrointestinal bleeding or excessive menstruation in women. The causes of anemia are mostly due to diseases of the blood system, such as iron deficiency anemia, megaloblastic anemia, aplastic anemia, and leukemia. The causes of anemia include insufficient or reduced red blood cell production, excessive red blood cell destruction, blood loss, etc. Insufficient red blood cell production is related to factors such as bone marrow hematopoietic function, hematopoietic microenvironment, and hematopoietic substances, while increased red blood cell destruction is mainly due to hemolytic anemia. Both of the above conditions require a visit to the hematology department to find out the specific cause of the anemia by checking the routine blood tests, bone marrow hematopoietic function, and other tests. Hematology is a department that treats and diagnoses various blood system diseases, and the common cause of anemia is the abnormality of the blood system, so anemia is usually treated in hematology, and if accompanied by anemia caused by other diseases, it is recommended to go to the relevant departments for consultation and active correction of anemia.