Above all, the bleeding can be responsible for anemia: either hemorrhage are externalized and therefore visible and diagnosed quickly, trauma, childbirth, surgery. Elsewhere, they may be difficult to diagnose a stomach ulcer bleeding a little too abundant rules … We must stop the bleeding. Sometimes anemia is such that we must make transfusions of one or more red blood cells (i.e. red blood cells).This anemia is regenerative, i.e. that the bone marrow will produce new red blood cells. Hemolytic anemia is anemia where red blood cells are destroyed too quickly or because the membrane of red blood cells is abnormal or too fragile, it may also exist antibodies against red blood cells that destroy or enzyme deficiency is the case of thalassemia, the anemia (hereditary diseases) …  Some poisoning by chemicals such as benzene, alcohol can also cause anemia. It is also the case of certain infectious diseases such as malaria, viral diseases, cancer, diseases system such as Systemic Lupus Erythematosus, inflammatory diseases can lead to weakening and destruction of red blood cells. Hemolytic anemia are also regenerative anemia. Other anemia due to decreased production of red  blood cells by bone marrow, they are regenerative: Some deficiencies cause anemia by preventing the formation of red blood cells: malnutrition whose origin may be a digestive disorder that leads to poor absorption of vitamins and minerals; origin may be food with a low intake of vitamins or Minerals in relation to consumption: iron deficiency during pregnancy, for example, deficiencies in folic acid (vitamin B9), vitamin B12 in people with chronic gastritis or advanced mastectomy. Medicines in particular chemotherapy can reduce the synthesis of red blood cells. Other conditions such as cancers that invade the bone marrow (leukemia) give anemia.