Anemia does not cause leukemia, but leukemia can cause anemia. There are many causes of anemia in children, including poor erythropoiesis, increased destruction of red blood cells, and loss of red blood cells. The anemia caused by childhood leukemia is only part of the poor erythropoiesis. In children with leukemia, the tumor cells in the body are constantly growing and occupying the normal bone marrow space, so there is no way for the normal blood cells to grow. Therefore, leukemia can cause anemia, but anemia does not cause leukemia.