Leukemia happens when cells in the blood, bone marrow, or lymphatic system develop abnormally and grow out of control. Leukemia is commonly thought of as cancer of the white blood cells as this is the most common form of leukemia.
Leukemia is classified based on the cell type and how quickly the cancer grows.
Slow-growing leukemia is called chronic leukemia—regardless of where it starts (i.e., the lymphoid cells or myeloid cells). Faster growing leukemia is called acute leukemia.
Some types of leukemia are more common in certain populations. For example, leukemia is the most common type of cancer found in children and teenagers, making up about 33% of all cancers of childhood cancers. Acute lymphocytic leukemia tends to happen more commonly in children than adults. It sometimes goes by the acronym ALL for short.
Acute Myeloid Leukemia, or AML, goes by several different names. These include acute myelocytic leukemia, acute myelogenous leukemia, acute granulocytic leukemia, and acute non-lymphocytic leukemia. AML is the second most common type of leukemia in adults.
Chronic lymphocytic leukemia (CLL) is leukemia of the white blood cells, or lymphocytes, in the bone marrow. One of the most common forms of leukemia, CLL mainly occurs in people age 20 or older and accounts for roughly 38% of all adult leukemias.
Chronic myeloid leukemia, also called chronic myelogenous leukemia or CML for short, starts in the bone marrow before eventually invading blood cells. CML makes up about 1 in every 10 leukemia cases.
Common signs and symptoms associated with leukemia include: