The causes of anemia include erythropoietic disorders, increased destruction of red blood cells and hemorrhagic anemia. 1. Erythropoietic disorder: Commonly, there are insufficient raw materials for hematopoiesis, such as iron, folic acid, vitamin B₁₂ deficiency, and it can also be seen in the bone marrow hematopoietic dysfunction, such as aplastic anemia, leukemia, and so on. 2. Increased destruction of red blood cells: common hypersplenism, immune hemolysis, thalassemia, acquired paroxysmal hemoglobinuria. 3. Hemorrhagic anemia: common traumatic bleeding, anemia due to excessive menstruation, chronic bleeding due to peptic ulcer, etc. Anemia patients are recommended to consult the doctor in time, actively improve the relevant examination to clarify the cause of the disease, and carry out regular treatment under the guidance of the doctor.