Leukemia is estimated to account for almost 1 out of 3 cancers in children and teens. It is a cancer that develops in the bone marrow. In this cancer, the bone marrow begins to make faulty white blood cells, but the reason remains unknown. The white blood cells help fight infection, but in leukemia, the abnormal white cells do not fight infection well. They faulty cells reproduce very quickly and crowd the bone marrow, thus reducing the production of red blood cells or platelets. While the red blood cells carry oxygen to different parts of the body, platelets help with blood clotting to stop bleeding. Common symptoms of leukemia include tiredness, problems with infections and bruising or bleeding and bone pain. On this occasion of World Blood Cancer Day, have listed the factors that are liked to increased risk for leukemia in children.