Uterine fibroids, which are also known as leiomyomas, are non-cancerous tumors, or growths that can grow on the outer wall of the uterus, within the muscle wall of the uterus, or on the inside wall of the uterus. They can change the shape of the uterus as they grow. If not taken care of, the size, shape, location, and symptoms of fibroids can change.
Fibroids do not grow before the start of menstrual periods (puberty). As women age, they are more likely to have uterine fibroids, especially from their 30s and 40s through menopause (typically around age 50). Uterine fibroids can stay the same for years with few or no symptoms, or you can have a sudden, rapid growth of fibroids.
During pregnancy fibroids sometimes grow larger in the first trimester, and they usually shrink for the rest of a pregnancy. After menopause, when a woman’s hormone levels drop, fibroids usually shrink and don’t come back.
Complications of uterine fibroids aren’t common. They can include:
- Anemia from heavy bleeding.
- Blockage of the urinary tract or bowels, if a fibroid presses on them.
- Ongoing low back pain or a feeling of pressure in the lower abdomen (pelvic pressure).
- Infection or a breakdown of uterine fibroid tissue.