Leukemia is a cancer of the early blood-forming cells. Most often, leukemia is a cancer of the white blood cells, but some leukemias start in other blood cell types. Leukemia is often described as being either acute (fast-growing) or chronic (slow-growing). Different types of leukemia have different treatment options and outlooks:
Acute Lymphocytic Leukemia (ALL) in Adults:
Acute lymphocytic (or lymphoblastic) leukemia is sometimes called ALL. It starts in the bone marrow where blood cells are made. It is more common in children than in adults.
Acute Myeloid Leukemia (AML):
Acute myeloid leukemia is also called acute myelocytic leukemia, acute myelogenous leukemia, acute granulocytic leukemia, acute non-lymphocytic leukemia, or sometimes just AML. It is most common in older people.
Chronic Lymphocytic Leukemia (CLL):
Chronic lymphocytic leukemia (CLL) is a type of cancer that starts in white blood cells (called lymphocytes) in the bone marrow. CLL mainly affects older adults and accounts for about one-third of all leukemias.
Chronic Myeloid Leukemia (CML):
Chronic myeloid leukemia (CML) is also known as chronic myelogenous leukemia. It's a type of cancer that starts in the blood-forming cells of the bone marrow and invades the blood. About 15% of leukemias in adults are CML.
Chronic Myelomonocytic Leukemia (CMML):
Chronic myelomonocytic leukemia is a type of cancer that starts in blood-forming cells of the bone marrow and invades the blood. It affects mainly older adults.
Leukemia in Children:
Leukemia is the most common cancer in children and teens, accounting for almost 1 out of 3 cancers. Most childhood leukemias are acute lymphocytic leukemia (ALL). Most of the remaining cases are acute myeloid leukemia (AML). Chronic leukemias are rare in children.
Symptoms vary by type of leukemia. Most signs and symptoms result from shortages of normal blood cells, which happen when the leukemia cells crowd out the normal blood-making cells in the bone marrow. These shortages show up on blood tests, but they can also cause symptoms, including:
- Bleeding, such as frequent or severe nosebleeds and bleeding gums
- Bruising easily
- Feeling dizzy or lightheaded
- Feeling tired
- Feeling weak
- Infections that don’t go away or keep coming back
- Loss of appetite
- Night sweats
- Shortness of breath
- Weight loss
Risk factors vary by type of leukemia, but general causes may include:
- Exposure to high levels of radiation
- Exposure to certain chemicals, including benzene
- Family History
- Genetic mutations/inherited syndromes