Hematologic oncology is the branch of medicine which deals with the study, diagnosis, treatment, and prevention of many diseases related to blood. Haematology involves the study of etiology. It involves the treatment of diseases which usually affect the production of blood and its components; it includes blood cells (RBC, WBC, etc…), haemoglobin, blood proteins, bone marrow, spleen, and also mechanism of coagulation. These kinds of diseases include hemophilia, blood clots, other bleeding disorders and mostly blood cancers such as leukaemia, myeloma, and lymphoma. Blood cancers affect the production of most of the blood cells in the body. These types of cancers start in patient’s bone marrow where the blood is produced. Stem cells mature and develop into three types of blood cells, which are White blood cells, red blood cells or platelets; they are smallest type of blood cell present in the bone marrow. The normal growth of blood cell is stopped by the uncontrolled growth of abnormal blood cells, which are generally cancerous.