Children usually get leukemia because of biological factors, physical factors, chemical factors, genetic factors and so on. 1. Biological factors: for example, viral infection, coupled with abnormal immune function can increase the risk of leukemia. 2. Physical factors: For example, repeated X-ray examinations are not recommended because ionizing radiation can cause leukemia. 3. Chemical factors: frequent exposure to cancer-causing chemicals can induce leukemia in children. 4. Genetic factors: In certain children with hereditary diseases, such as Down syndrome, congenital testicular hypoplasia, congenital aplastic anemia with multiple malformations, congenital distal capillary dilatation erythema, and severe combined immunodeficiency disease, etc., the incidence of leukemia is significantly higher than that of children in general. In order to prevent leukemia, children should stay away from undesirable triggers, stay away from some cancer-causing factors, let the children develop good living habits and dietary habits, and do not blindly do X-ray examination many times. If you find that your child has abnormal symptoms, you should go to the hospital in time and consult a physician for guidance.