Multiple myeloma occurs when plasma cells in the bone marrow multiply to excess. Plasma cells are white blood cells that produce antibodies to fight infections.
Bone marrow is the soft, fatty tissue inside bones.
As a result of the disease, bone marrow does not produce the parts of the blood as it normally does, bones are weakened, and the few normal plasma cells are less able to fight infection. Other complications of this life-threatening cancer include anemia, paralysis, blood clotting problems, nerve damage, and kidney failure. This disorder affects mainly people over age 50. For reasons doctors don't yet fully understand, multiple myeloma occurs when abnormal plasma cells multiply quickly and disturb the number of red blood cells, white blood cells, and platelets being made. The rapidly multiplying plasma cells generally all produce the same defective, inactive antibody.