Acute Leukemia

With acute leukemia, immature blood cells reproduce quickly in the bone marrow, where they eventually crowd out healthy cells. When present in high numbers, these immature, abnormal cells sometimes can spread to other organs, causing damage, especially in a type of leukemia called acute myeloid leukemia. The two main types of acute leukemia involve different types of blood cells:

Acute lymphoid leukemia is the most common type of leukemia that affects children, mainly those younger than 10. Adults sometimes develop acute lymphoid leukemia, but it is rare in people older than 50. It occurs when primitive blood-forming cells called lymphoblasts reproduce without developing into normal blood cells. These abnormal cells crowd out healthy blood cells. They can collect in the lymph nodes and cause swelling.


Acute myeloid leukemia accounts for 50% of leukemia diagnosed in teenagers and in people in their 20s. It is the most common acute leukemia in adults. It occurs when primitive blood-forming cells called myeloblasts reproduce without developing into normal blood cells. Immature myeloblast cells crowd the bone marrow and interfere with the production of healthy normal blood cells. This leads to anemia (not having enough red blood cells), bleeding and bruising (due to a lack of blood platelets, which help the blood to clot), and frequent infections because there are not enough protective white blood cells.