Multiple myeloma is a cancer of the body's plasma cells. Plasma cells are a type of white blood cell, and they are part of the body's immune system. When they are normal, they help fight infection and disease. In people with multiple myeloma, plasma cells become cancerous, and the body produces too many of them.

Various medical studies have found that growing older increases a person's risk of developing multiple myeloma. Most people that are diagnosed with multiple myeloma are 65 years of age or older. Other studies have found that African-Americans have the highest risk of developing multiple myeloma, and that Asian-Americans are the least likely to develop multiple myeloma. However, the reasons for this difference are unknown.

Read more about multiple myeloma and your bones.

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