Introduction

Leukemia is cancer of the blood cells, usually the white blood cells. Acute lymphocytic leukemia is also known as ALL and acute lymphoblastic leukemia. ALL is the most common leukemia in children. However, about one-third of all cases of ALL occur in adults. About 5,430 people in the United States will be diagnosed with ALL in 2008, according to the American Cancer Society.

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases make up the body’s lymph system. ALL occurs when bone marrow and the lymph system produce too many immature lymphocytes. Lymphocytes are white blood cells that fight infection by making antibodies that attack harmful organisms.

The word "acute" means sudden or rapid in onset. Acute leukemia can occur in a short period of days or weeks. A person with ALL has immature lymphocytes that cannot function properly to fight infection. They crowd out other blood cells and may collect in blood, bone marrow, and lymph tissue. People with ALL have trouble fighting infection. They may bleed and bruise easily because they do not produce enough platelets. Platelets are a type of blood cell that helps make blood clot. People with ALL do not make enough red blood cells, which carry oxygen through the body. When this happens, they get anemia, which makes them feel weak and tired.

In most cases, it is impossible to know what caused someone to develop ALL. However, radiation exposure can increase the risk of developing ALL. This could happen as a result of a nuclear power accident. Some people suspect that electrical fields from high-voltage power lines may also increase the risk of ALL. However, studies have not shown a clear link so far. Lifestyle behaviors, such as smoking and poor diet, do not seem to increase the risk of ALL.