There are several types of anemia, some are iron deficiency and some are nutritional. Malnutrition anemia is more common in patients with eating disorders or long-term diarrhea. In addition to the general symptoms of anemia such as dizziness, tinnitus, vertigo, fatigue, dry and falling hair, patients may also suffer from loss of appetite, diarrhea, aphtha, glossitis, etc. , and some are hereditary. Leukemia is mainly caused by low blood immunity, poor defense ability, and severe vitamin C deficiency. They are all blood problems. We can only say that anemia will increase the possibility of leukemia, but we cannot say that it is caused by anemia. Anemia is most common in women. Iron is an important trace element for hematopoiesis. Iron deficiency in the diet is the main cause of anemia. In addition, hookworm infection, gastrointestinal malabsorption, gastric and duodenal ulcer bleeding, hemorrhoidal bleeding, menorrhagia in women, and functional uterine bleeding in adolescence can all cause iron deficiency anemia. Its performance is similar to that of malnutrition anemia, which can be identified by testing the trace elements in the hair. It can only be said that anemia will increase the possibility of leukemia, but it cannot be said that it is caused by anemia. The faster anemia occurs, the more serious the symptoms will be, while the symptoms of anemia that appear slowly will be relatively mild due to the body's adaptation and compensation, which is the process of continuous renewal of red blood cells in the body. The lifespan of red blood cells in circulating blood is approximately 120 days, and aged red blood cells are mainly eliminated in the spleen. Bone marrow is the factory where adults make red blood cells. Immature red blood cells develop and grow in the bone marrow. After maturity, they are continuously transported into the blood circulation to maintain a constant amount of red blood cells and hemoglobin in the circulating blood. Therefore, reduced red blood cell production or excessive red blood cell loss results in anemia. Excessive loss of red blood cells caused by various reasons shortens the life of red blood cells and causes excessive and rapid destruction, which results in hemolytic anemia; excessive blood loss causes hemorrhagic anemia. In addition, chronic infection, tumors, nephritis, uremia, liver disease, endocrine dysfunction, etc. can be accompanied by anemia symptoms. This type of anemia is called secondary anemia.