Fibroids are growths of the uterus, or they are also called uterine leiomyomas or myomas. The uterus is made of muscle and fibroids grow from muscle. Fibroids can bulge from inside or outside the uterus. Fibroids are not cancerous and are not believed to become cancerous. Fibroids are very common. Approximately 80 percent of women will have fibroids in their lives, although not all of these women have bothersome fibroid symptoms. Treatments are available for women who have fibroid related problems, such as heavy menstrual bleeding, pain or pressure in the pelvis, or problems with pregnancy or infertility.