The types of leukemia are grouped according to cell type and the course of the disease. The words, myelogenous and lymphocytic describe the type of white blood cell.

Leukemias may be either acute or chronic. Acute leukemia starts abruptly and the cells grow very rapidly. Acute leukemia is more common in children. Chronic leukemias grow more slowly, and are most common in adults.

The most common types of leukemia include:

• Acute lymphocytic leukemia (ALL):
• Most common form in children
• Acute myelogenous leukemia (AML):
• Most common form in adults
• Chronic lymphocytic leukemia (CLL)
• Chronic myelogenous leukemia (CML)