Fibroids are pale, firm masses that sometimes form in the wall of the uterus. They result from abnormal cell development. These tumors are almost always benign and can range in size from a tiny speck to large masses that can distort the uterus and nearby organs.

Uterine fibroids usually appear during the reproductive years and tend to grow slowly over time. There are three main types of fibroids: subserosal (which grow in the outer wall of the uterus), intramural (which develop in the muscular layers of the uterine wall) and submucosal (which protrude into the uterine cavity).

Sometimes a subserosal or submucosal fibroid may develop a stalk (peduncle), similar to the stem of a plant, and hang in the uterus. These fibroids are known as pedunculated, and as they enlarge they may twist on the stalks, causing severe pain and requiring emergency treatment.

The exact causes of fibroids are not understood. But research indicates that genetics, race or ethnicity, hormonal changes and obesity may be contributing factors in development. The condition also is more prevalent among African-American women. When women with uterine fibroids stop menstruating (menopause), the fibroids usually shrink or disappear altogether.

Most uterine fibroids are small and do not produce any symptoms. In many cases, women may not be aware that they have fibroids until the gynecologist discovers them during a routine pelvic examination.

If symptoms occur they are related to the number, size and location of the fibroids. Symptoms of fibroids can include menorrhagia, severe menstrual cramps and pelvic pain as well as bladder and bowel problems, such as urinary tract infections, incontinence and constipation.

Depending upon the uterine location, fibroids sometimes may interfere with the ability to get pregnant or cause miscarriage. Although fibroids do not usually cause infertility, the condition is associated with pregnancy complications including placenta previa and premature delivery.

To confirm a diagnosis of uterine fibroids and rule out other conditions, a physician will order several tests including imaging tests (e.g., ultrasound, hysteroscopy), blood tests and endometrial biopsy.

In most cases, fibroids do not require treatment. This is especially true if symptoms are not present. When symptoms are present, treatment will depend on several factors including the severity of the symptoms, the age of the patient and whether she plans to become pregnant in the future. There are several treatment options for fibroids including medications (e.g., hormonal therapy) and in some cases surgery (e.g., myomectomy, hysterectomy).