Definition of Multiple myeloma:

Multiple myeloma is a cancer of the plasma cells in bone marrow.

Causes, incidence, and risk factors:

Plasma cells help the body's immune system fight disease. Multiple myeloma occurs when plasma cells grow out of control. Excessive plasma cells can form a tumor in the bone marrow called a myeloma. Many tumors are called multiple myeloma.

The growth of the excess plasma cells interferes with the production of red blood cells, white blood cells, and platelets. This causes anemia and makes a person more likely to get infections and have abnormal bleeding.

As the cancer cells grow in the bone marrow, they cause pain and destruction of the bones. If the bones in the spine are affected, it can put pressure on the nerves, resulting in numbness or paralysis.

Renal failure (kidney failure) is a frequent complication.

Multiple myeloma mainly affects older adults. A history of radiation therapy raises your risk for this type of cancer.