1. Malnutrition: For example, lack of B vitamins, folic acid and iron can all lead to anemia. The solution is to take in corresponding nutrients. For example, eating coarse grains can take in B vitamins and folic acid, and eating spinach and red dates can take in iron.

2. Congenital diseases-for example, thalassemia

3. Suffering from some diseases with hematopoietic dysfunction-for example, related to bone marrow.

4. Side effects of taking some drugs for a long time-for example, the side effects of some drugs can inhibit the regeneration rate of bone marrow cells.

5. Suffering from some diseases can consume a lot of body nutrition.

6. Some parasitic diseases.