Leukemia is cancer of blood-forming tissues, including bone marrow. Many types exist such as acute lymphoblastic leukemia, acute myeloid leukemia, and chronic lymphocytic leukemia. <br />Many patients with slow-growing types of leukemias don't have symptoms. Rapidly growing types of leukemia may cause symptoms that include fatigue, weight loss, frequent infections, and easy bleeding or bruising. <br />Treatment is highly variable. For slow-growing leukemias, treatment may include monitoring. For aggressive leukemias, treatment includes chemotherapy that's sometimes followed by radiation and stem-cell transplant.