Leukemia is cancer of the bone marrow and blood. It results from an uncontrolled buildup of abnormal blood cells. The four types of leukemia are named for the cell type—myeloid or lymphoid—and how quickly the leukemia grows. Chronic leukemia refers to mature cells that grow slowly, while acute refers to less developed cells that grow quickly.

• Acute Myelogenous Leukemia (AML) is the most common type of leukemia in adults.
• Chronic Lymphocytic Leukemia (CLL) is the second most common type of leukemia in adults.
• Chronic Myelogenous Leukemia (CML) is the third most common type of leukemia.
• Acute Lymphocytic Leukemia (ALL) is the least common type of leukemia and primarily affects children.