Multiple Myeloma Risk Factors

History of monoclonal gammopathy of undetermined significance (MGUS)

MGUS is a plasma cell disorder that has the potential to develop into multiple myeloma. A plasma cell is a type of white blood cell that makes antibodies to help the body fight infection. Many of the known and possible risk factors for MGUS are the same as for multiple myeloma.

Family history of multiple myeloma

Multiple myeloma is more common in some families. The risk of developing multiple myeloma is nearly 4 times greater for a person who has a parent or sibling with multiple myeloma. Some studies show that there is a stronger risk in families of African ancestry. But most people with multiple myeloma have no family history of the disease.

Obesity and overweight

Multiple myeloma occurs more often in people with a high body mass index (BMI) than in those who have a healthy weight.


Many studies show that people who work on a farm have a higher risk of developing multiple myeloma. We need more research to understand what it is about farming that causes the increase in risk. Some studies suggest that being exposed to certain pesticides used in farming explains the increased risk. Pesticides include many chemicals, but only some pesticides are linked to multiple myeloma risk. Research also shows that working with farm animals, especially sheep, may increase your risk. It may be that it is the combination of being exposed to pesticides, animals, or other factors that increases a person’s chance of developing multiple myeloma.

Weakened immune system

People with a weakened immune system (immunosuppression) have a higher risk of developing multiple myeloma. This includes people with HIV or AIDS and people who have had an organ transplant and must take medicines to suppress their immune system.


The information found on this page was provided by the Canadian Cancer Society.