γγThe basic causes of anemia are as follows: 1, nutritional anemia: megaloblastic anemia caused by vitamin B12 and folic acid deficiency, methemoglobin underground anemia, protein and vitamin C deficiency anemia, iron deficiency anemia.γγ2, bone marrow failure anemia: congenital pure red blood cell aplastic anemia and acquired pure red blood cell aplastic anemia; triple lineage cell failure anemia including institutional, Fanconi anemia, familial complementary malformation reduplication, congenital dyskeratosis, acquired aplastic anemia (idiopathic, secondary); bone marrow infiltrated (leukemia, lymphoma, neuroblastoma, etc.)