Myeloma, also known as multiple myeloma, is a type of bone marrow cancer arising from plasma cells, which are normally found in the bone marrow. Plasma cells form part of your immune system.

Normal plasma cells produce antibodies (also called immunoglobulins) to help fight infection. In myeloma, abnormal plasma cells release only one type of antibody known as paraprotein, which has no useful function. It is often through the measurement of this paraprotein that myeloma is diagnosed and monitored.