The causes of low hemoglobin in children mainly include the following: 1, caused by iron deficiency in the body, if there is a serious iron deficiency, will cause iron deficiency anemia, hemoglobin concentration will be significantly low, need to usually eat more pig blood, duck blood and other blood products. If it is more serious, you can take oral ferrous succinate. 2, due to the symptoms caused by hemolysis, some children suffer from sericea, sericea is caused by the lack of G6PD enzyme in the body, after eating sericea will cause the destruction of red blood cells, causing jaundice, anemia and other symptoms, resulting in a significantly low concentration of hemoglobin, this situation is also very common.