Multiple myeloma overview

Multiple myeloma is a cancer of the special white blood cells that produce antibodies, also known as plasma cells. Multiple myeloma affects the bone marrow, which is the spongy inner part of bones where blood cells are made.

Diagram showing plasma cells within bone marrow. In multiple myeloma, plasma cells become cancerous and multiply.

How multiple myeloma develops

Myeloma cells can multiply quickly and can build up in the bone marrow, crowding out healthy blood cells. Myeloma cells often produce large quantities of an abnormal antibody, called M protein (also known as monoclonal protein or monoclonal immunoglobulin) and keep healthy bone marrow from making enough blood cells for the body to fight infections and other diseases. M protein is found in unusually large amounts in the blood or urine of many people with multiple myeloma. Myeloma cells can cause bone damage, kidney impairment, and anemia. Anemia is a low level of red blood cells or hemoglobin and can cause several symptoms, including shortness of breath, weakness, and fatigue.

Active elderly women.

Signs and symptoms of multiple myeloma

People with multiple myeloma may experience a number of symptoms that lead them to seek medical attention. However, some people may not have any symptoms, or their symptoms may be vague.

Symptoms may include:

  • Confusion, thirst, loss of appetite, irregular or abnormal heartbeat (arrhythmia)
  • Fatigue, changes in urination, swelling in legs and feet
  • Shortness of breath, rapid heartbeat
  • Bone pain, fractures, spinal cord compression

These symptoms are known by the acronym CRAB that stands for:

Letter C icon.

levels increased in blood

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(kidney) problems

Letter A icon.


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Multiple myeloma diagnosis

Recent studies have uncovered signs of multiple myeloma that can be detected by advanced lab tests and imaging. These signs, or biomarkers, are known by the acronym SLiM and are defined below. Testing for these biomarkers allows healthcare professionals to diagnose and treat multiple myeloma earlier and help prevent organ damage.

Letter S icon.

Sixty percent or greater clonal bone marrow plasma cells—excessive production of abnormal plasma cells (also known as myeloma cells) in the bone marrow.

Letters L and i icon.

Light chain ratio of 100 or greater in the blood serum—excessive plasma cell production in myeloma causes the ratio between 2 types of light chain proteins found in blood to be unbalanced by a factor

Letter M icon.

MRI with more than 1 focal lesion—magnetic resonance imaging shows an abnormality in part of the bone or bone marrow.

When multiple
myeloma returns

Learn about signs and symptoms when
multiple myeloma comes back


Find out how NINLARO works by
binding to proteasomes inside cells.