Multiple myeloma causes and risk factors

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science

This page was updated on June 6, 2022.

The lifetime risk of getting multiple myeloma is relatively small. According to the American Cancer Society (ACS), the average lifetime risk of getting multiple myeloma is about 1 in 103 for men and about 1 in 131 for women.

Multiple myeloma develops when an irregular plasma cell multiplies in the bone marrow, subsequently forming tumors throughout the bone marrow that crowd out normal blood cells.

What causes multiple myeloma?

While the exact cause of multiple myeloma may not be known, several factors may increase the risk of developing the disease. In particular, a condition known as monoclonal gammopathy of unknown significance (MGUS) is known to increase a person's risk for developing myeloma.

Is multiple myeloma hereditary?

The mutations that lead a person to develop multiple myeloma are not inherited, but a family history of the disease does raise a person's risk of developing myeloma. Having a sibling or a parent who’s had multiple myeloma may increase the likelihood of developing the disease as much as four times when compared to people who have no family history of multiple myeloma. However, this has only been found in a small number of cases.

Learn more about genetic testing

Multiple myeloma risk factors

Race: For unknown reasons, the incidence of multiple myeloma is twice as high in African Americans as in Caucasians.

Gender: Men have a slightly higher risk than women for developing the disease.

Age: Only a very small percentage of young adults are diagnosed with multiple myeloma. The majority of those diagnosed are over 65 years old.

Obesity: Research has found that obesity may lead to an increased risk of multiple myeloma.

Personal history of MGUS: Some people who have MGUS may be at increased risk for multiple myeloma. In MGUS, an abnormal line of antibody-producing plasma cells will begin to produce monoclonal antibody proteins (M proteins). Over time, the proliferation of the M protein may crowd out the normal plasma cells that produce functional antibodies. The ACS has reported that, every year, approximately 1 percent of all people with MGUS develop a more severe disease, including multiple myeloma. It is not known why some people with MGUS develop multiple myeloma and others do not.

Radiation exposure: A small number of cases may be linked to exposure to high doses of radiation.

Next topic: What are the symptoms of multiple myeloma?

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