Leukemia is a cancer of the blood that affects both males and females of all ages. While the exact causes are unknown, radiation, viruses, and chemicals may play a role. Symptoms include fever, body aches, fatigue and weakness. Leukemia cannot be transmitted but some may have a genetic predisposition. It is detected through blood tests, biopsies and other medical exams. Leukemia can be either acute or chronic and affects the blood and bone marrow, replacing healthy blood cells and leaving the body vulnerable to infection. While there is no prevention, treatment may involve chemotherapy, radiation or stem cell transplants, and some types are curable though others can be terminal.