Fibroids are benign (noncancerous) growths in the wall of the uterus. The uterus is the organ where a fetus grows during pregnancy.

Fibroids are common. They may be very small or they could grow to eight or more inches in diameter. Most fibroids remain inside the uterus. Sometimes, they may stick out and affect nearby organs. It is common for there to be more than one fibroid.

Uterine Fibroid
Copyright © Nucleus Medical Media, Inc.

The cause of fibroids is unknown.

Fibroid growth is stimulated by female reproductive hormones. As a result:

Genetics may make some women more prone to fibroids. Substances that control blood vessel growth may also affect fibroid growth.