Multiple myeloma is cancer of the plasma cells, a type of white blood cell present in bone marrow that enable the body to fight infection. It causes abnormal plasma cells to accumulate in the bones or bone marrow and interferes with the production of blood cells and can cause bone lesions. Symptoms may vary and at first may go unnoticed. They may eventually affect kidney function, bone fractures, weakness or numbness in the legs, infections and weight loss. There is no cure for the condition but there are treatment options available.