Uterine fibroids are noncancerous growths of the uterus that often appear during childbearing years. Also called leiomyomas (lie-o-my-O-muhs) or myomas, uterine fibroids aren't associated with an increased risk of uterine cancer and almost never develop into cancer.
Fibroids range in size from seedlings, undetectable by the human eye, to bulky masses that can distort and enlarge the uterus. You can have a single fibroid or multiple ones. In extreme cases, multiple fibroids can expand the uterus so much that it reaches the rib cage and can add weight.
Many women have uterine fibroids sometime during their lives. But you might not know you have uterine fibroids because they often cause no symptoms. Your doctor may discover fibroids incidentally during a pelvic exam or prenatal ultrasound.
Many women who have fibroids don't have any symptoms. In those that do, symptoms can be influenced by the location, size and number of fibroids.
In women who have symptoms, the most common signs and symptoms of uterine fibroids include:
Rarely, a fibroid can cause acute pain when it outgrows its blood supply, and begins to die.
Fibroids are generally classified by their location. Intramural fibroids grow within the muscular uterine wall. Submucosal fibroids bulge into the uterine cavity. Subserosal fibroids project to the outside of the uterus.
There are few known risk factors for uterine fibroids, other than being a woman of reproductive age. Factors that can have an impact on fibroid development include: