Chronic myelogenous leukemia (CML) is a cancer that affects your blood cells and bone marrow -- the soft part inside your bones where blood cells are made. You may also hear your doctor call it chronic myeloid leukemia. It's the same disease, just a different name.

With treatment, you may go into what's called "remission." For most people, that doesn't mean the cancer is completely gone, but it's less active than before. You can be in remission for many years.

CML usually happens when you're middle-aged or older. The symptoms tend to come on gradually. Many of them can also be signs of other illnesses. For instance, you might feel tired, lose weight when you're not trying to, or sometimes get a fever.