What is Multiple Myeloma?

Multiple myeloma is the second most common blood cancer in the U.S. There are more than 77,000 people living with multiple myeloma in the U.S. The disease is more common in men than in women.

Multiple myeloma is a cancer of the plasma cells, a type of white blood cell that develops in the bone marrow. Plasma cells make antibodies and help the immune system fight off infection and disease. In people with multiple myeloma, the plasma cells become abnormal and produce a protein called an M protein. When these abnormal plasma cells multiply, they can create bone lesions tumors that can cause damage to the bones and lead to pain.

Multiple myeloma can be categorized into three groups:
  • Monoclonal gammopathy of undetermined significance (MGUS): A precursor to multiple myeloma. In a person with MGUS, a low level of M protein is present but the condition is usually not accompanied by symptoms and usually causes no problems. People with MGUS may develop multiple myeloma over time. If you have MGUS, you will usually have periodic checkups to monitor your level of M protein. If there is no increase, MGUS does not require treatment.
  • Smoldering or asymptomatic myeloma: A slightly higher level of M protein is present but the person does not have symptoms of multiple myeloma. Most people with smoldering myeloma develop multiple myeloma, and are closely monitored for signs that the cancer is growing.
  • Symptomatic myeloma: A person with symptomatic myeloma experiences common symptoms of multiple myeloma, which can lead to infections, abnormal bleeding and fatigue, and/or bone pain and possibly numb or weak feelings in the legs or arms.

Updated on October 28, 2014