Cancer and Healthy

Leukemias are cancers of the blood and occur when there is an excess accumulation of abnormal (immature) blood cells (called explosion). Instead of normal maturing, large numbers of these cells change in explosion abnormal white blood cells. These abnormal cells can not carry out the normal functions of white blood cells. They crowd the bone marrow and spill into the bloodstream and can then in organs like the liver, spleen, lungs, kidneys and in the cerebro spinal fluid into the brains.

In leukemia, the cells do not mature properly, but continue to multiply and the bone marrow is replaced by abnormal cells spilling over into the blood. Because the bone marrow can no longer enough normal blood cells and platelets, anemia, infections and bruising occurs.

Leukemia is present in various forms. Some forms appear suddenly and progress rapidly over days to weeks. These are the so-called acute leukemias. Others are less visible and progress slowly over months to years. These are the chronic leukemias. Leukemia is also described according to the type of white blood cell involved; granulocytes (formed from immature cells called myeloblasts), or lymphocytes. The four main types of leukemia are:

* Acute lymphoid leukemia (ALL) - generally occurs in young children, but can occur in adults.
* Acute myeloid leukemia (AML) - usually occurs in adults, but can occur in children.
* Chronic myeloid leukemia (CML) - can occur at any age but is uncommon below the age of 20 years.
* Chronic Lymphoid Leukemia (CLL) - usually occurs in older people and is rare under the age of 35 years.