Leukemia is a type of blood cancer characterized by an abnormal increase of white blood cells. Symptoms can include flu-like symptoms, fever, weight loss, infections, headaches, skin rash, bone pain, and easy bruising. Treatments include chemotherapy, which uses drugs to kill cancer cells, and radiation treatments, which use high-energy rays to shrink blood tumors. Leukemia affects over 256,000 children and adults each year and damages the bone marrow.