Acute leukemia is a type of cancer of the blood and bone marrow cells. "Acute" indicates that the leukemia develops and advances quickly and requires immediate medical attention. In patients with acute leukemia the bone marrow produces an excessive amount of abnormal immature white blood cells which do not function normally. Patient may have low amounts of normal blood cells. There are 2 main types of acute leukemia, acute myeloid leukemia and acute lymphoblastic leukaemia.