Leukemia is when the bone marrow produces abnormal cells (blast cells and other types of abnormal cells). It increases in many cases the total count of WBC, enormously, the patient experiences temperature on and off, progressive anaemia, and fatigue and weakness. In many cases there is enlargement of the spleen. There are 3-4 types of blood cancers. Acute Myeloid Leukemia, Chronic Myeloid Leukemia, Acute Lymphoblastic Leukemia, and Chronic Lymphoblastic Leukemia.