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What are Uterine Fibroids?

By Joan Bengtson, M.D.
Content provided by the Faculty of the Harvard Medical School

Joan Bengtson, M.D., is assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and a


I recently had a CT scan that found a fibroid in my uterus. What is a fibroid? Can it be a problem?


Fibroids are noncancerous (benign) tumors of muscle cells that grow in the wall of the uterus. Fibroids may occur in up to 75% of women. They cause symptoms in only about 25%. Fibroids tend to grow during the reproductive years when hormone activity is high. Fibroids shrink after menopause when hormone levels drop. The cause of fibroids is unknown.

A woman with fibroids may have no symptoms. The fibroid may only be diagnosed when the tumor is detected during a physical exam or by a CT scan or ultrasound that was used for an unrelated problem. Fibroids that cause no symptoms do not require treatment. However, your doctor may suggest regular pelvic exams to monitor the fibroid's growth.

Symptoms caused by fibroids include:

  • Pelvic pain

  • Pressure

  • Heavy menstrual bleeding

Some women have spotting (light bleeding) between periods. If the fibroids are large, they may cause difficulty with urinating or bowel movements or an unusually frequent need to urinate. Fibroids do not typically cause infertility, but they may grow during pregnancy and are associated with a higher miscarriage rate than average.

There are many ways to treat fibroids if treatment is needed. You and your doctor will make the choice between medical and surgical options or one of the newer approaches. Your age, pregnancy plans, symptoms, and characteristics of the fibroids will be taken into account in choosing the best treatment for you.

Last Annual Review Date: 2011-01-11T00:00:00-07:00 Copyright: Copyright Harvard Health Publications

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