May also be called: Acute Lymphocytic Leukemia; ALL

What Is Acute Lymphoblastic Leukemia?

Acute lymphoblastic leukemia (ALL) is a type of cancer that causes the body to make too many abnormal immature white blood cells (called lymphoblasts).

Normally, white blood cells help fight infection and protect the body against disease. In acute lymphoblastic leukemia (lim-fo-BLA-stik loo-KEE-mee-uh), these cells turn cancerous and multiply, interfering with the body’s normal functions.

Symptoms include tiredness (fatigue), fever, bone pain (in the arms, legs, or ribcage), night sweats, infections that keep coming back, and easy bleeding and bruising. 

Doctors don't know what causes ALL, but it’s the most common type of leukemia in children.

What Else Should I Know?

Treatment for ALL involves chemotherapy to kill as many cancer cells as possible. Kids need to continue with chemo for several years to help prevent ALL from coming back.

Most kids with ALL are cured with treatment.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.