Leukaemia is cancer of blood cells that originates in the bone marrow. It often causes large numbers of white blood cells to be made, which appear in the blood stream either in abnormal numbers or abnormal size and shape under the microscope. These abnormal cells do not function properly, so the immune defense against infection is lowered. These abnormal cells also crowd the healthy bone marrow cells, and reduce the production of healthy cells as well, causing low red cell and platelet counts, and not enough healthy white cells. Leukaemia cells can spread into the lymph nodes, or to organs such as the spleen or liver, skin or gums. Occasionally leukaemia can spread into the brain, spinal cord or surrounding fluid.
There are four main types of leukemia:
Acute Myeloid Leukaemia (AML)
Acute Lymphoblastic Leukaemia (ALL)
Chronic Myeloid Leukaemia (CML)
Chronic Lymphocytic Leukaemia (CLL)
Acute leukaemias develop quickly, and need to be treated very urgently. Treatment is usually given in hospital. Chronic leukaemias tend to grow slowly over time. Some chronic leukaemias grow so slowly that it is appropriate to watch and wait rather than treat immediately.