Multiple myeloma is a cancer of certain white blood cells (WBC) in the bone marrow called plasma cells that are responsible for making antibodies (immunoglobulins). In Greek, the language of most medical terms, “myelo” refers to the blood-producing cells in the bone marrow, and “oma” refers to a tumor or mass of cancer cells. A malignant (cancerous) plasma cell is called a myeloma cell. In this section, learn more about multiple myeloma's symptoms and causes.

What Is Myeloma and Where Does It Grow?

Myeloma most often grows in the marrow within the bones of the spine, skull, pelvis, rib cage, shoulders, and hips. Usually, the bones of the hands and feet and lower parts of the arms and legs are not affected, preserving the function of these critical areas.

Myeloma can appear as both a tumor and/or as an area of bone loss. In either case, this is called a "lesion." Areas of bone loss caused by myeloma are referred to as "lytic lesions." The only time that myeloma is not "multiple" are in rare cases of a solitary plasmacytoma of bone (SPB) or an extramedullary plasmacytoma.

What Causes Multiple Myeloma?

Exposure to toxic chemicals, atomic radiation, anything that interferes with the immune system, or infection with cancer-causing viruses have all been implicated as causes or triggers of myeloma.

chart showing what toxic chemicals are known to trigger multiple myeloma

Toxic chemicals that have been identified include:

  • benzene
  • dioxins (such as those found in Agent Orange)
  • agricultural chemicals (such as defoliants and pesticides)
  • solvents
  • fuels
  • engine exhausts
  • cleansing materials

Several viruses have been identified as potential triggers, including:

  • HIV and AIDS
  • hepatitis
  • several herpes viruses
  • Simian virus 40 (a contaminant in Sabin polio vaccine preparations used between 1955-1963)

Multiple myeloma can also be hereditary. First-degree relatives of people with MM have a higher risk of developing the disease or its benign (non-cancerous) precursor, monoclonal gammopathy of undetermined significance (MGUS).

If you have a family member (mother, father, brother, sister, son, or daughter) with MM or MGUS, mention this to your primary care physician so it is in your permanent medical record. Your doctor can then be more aware of early symptoms and signs, and can order appropriate testing if necessary. If you have multiple myeloma, tell your family members to mention it to their doctors.

pie chart showing myeloma causes

Symptoms and Signs 

In 70% of patients, the most common symptoms of multiple myeloma are back or bone pain, fatigue, and recurrent or persistent infections. If you are experiencing any of the following possible symptoms, consult your physician.

  • Persistent or worsening tiredness
  • Recurrent unexplained infections (such as pneumonia, sinus infection, or urinary tract infection)
  • Back pain or any bone pain that is persistent or recurrent
  • Swelling of the extremities
  • Shortness of breath


The International Myeloma Foundation medical and editorial content team

Comprised of leading medical researchers, hematologist, oncologists, oncology-certified nurses, medical editors, and medical journalists, our team has extensive knowledge of the multiple myeloma treatment and care landscape. Additionally, Dr. Brian G.M. Durie reviews and approves all medical content on this website.

Last Medical Review: September 11, 2019

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