Fibroids are non-cancerous (benign) tumors that grow from the muscle layers of the uterus and affect at least 20 percent of women sometime during their lifetime. Depending on their size and location, fibroids may cause no symptoms at all or a variety of complications.
There are four primary types of uterine fibroids, classified by location:
The most common type of fibroids, intramural fibroid tumors develop within the muscles of the uterine wall and often expand from there. When an intramural fibroid expands, it tends to make the uterus feel larger than normal and can cause excessive menstrual bleeding, prolonged menstrual cycles and clot passing, frequent urination, and back and pelvic pain caused by the additional pressure placed on surrounding organs.
The least common type of fibroids, submucosal, are located in the muscle under the uterine lining (endometrium) and may protrude into the uterine cavity. Submucosal fibroids can cause heavy bleeding, prolonged menstrual cycles, and the passing of clots. Left untreated, prolonged or excessive bleeding can cause more complicated problems, such as anemia and fatigue. Submucosal fibroids are also most closely linked to fertility problems, as large tumors can block the fallopian tubes.
Subserosal fibroids grow on the outer wall of the uterus. They can become quite large, continuing to grow outward and putting increased pressure on surrounding organs. This type of fibroid does not usually interfere with a woman’s menstrual flow or cause excessive bleeding but can cause pelvic pain and pressure.
Subserosal, as well as submucosal, fibroids can sometimes develop into pedunculated fibroids, meaning they grow on a stalk. Pedunculated fibroids can twist on the stalk, causing additional pain and pressure.
Cervical fibroids are located in the wall of the cervix, the neck of the uterus. The most common symptom is irregular or heavy bleeding. Cervical fibroids can also cause painful sexual intercourse, vaginal discharge, or trouble with urination.
Women generally have multiple fibroids, and it is possible to have more than one type, making it difficult to determine which fibroid is causing symptoms.
If you are experiencing any of the following symptoms, you may have uterine fibroids:
- painful, heavy periods
- pelvic or back pain
- frequent or difficult urination
- swelling in the abdomen
- painful intercourse