Uterine fibroids are tumors, or growths, made up of muscle and other tissues that grow in the uterus. They may develop in the uterine wall, inside the lining of the uterus, or outside of the uterus. They occur in 20-25% of women of childbearing age, and up to 80% of women will suffer from fibroids at some point in their lives. A single fibroid may develop or several may develop in groups. Fibroids range in size from less than one inch to larger than the size of a grapefruit. Other names for fibroids are uterine leiomyomata, fibromyomas, leiomyomas, and myomas.
Many women with fibroids do not experience any symptoms and are unaware that they have fibroids. However, about one in four women may have heavy bleeding, pain, and urinary problems that require treatment. Fibroids are almost always benign (not harmful) and very rarely develop into cancer. Fewer than 0.1% of fibroid cases become cancerous. Other complications may include infertility, pregnancy problems, and anemia.
Any woman can develop fibroids; they are most common among African American women. The cause is unknown and there are no known ways to prevent them.
Fibroids are classified based on their location in the uterus and can be submucosal, intramural, subserosal, and pedunculated. Symptomatic fibroids can be treated with medications, surgeries, and other procedures. The most invasive surgery available, called a hysterectomy, completely removes the uterus and is the only treatment that completely prevents fibroids from growing back. One-third of hysterectomies in the United States are due to uterine fibroids.

Related Terms

Endometrial ablation, fibromyomas, focused ultrasound surgery, hysterectomy, intramural fibroids, leiomyomas, leiomyosarcoma, myomas, myomectomy, pedunculated fibroids, submucosal fibroids, subserosal fibroids, tumors, uterine fibroid embolization, uterine leiomyomata, uterus.

types of the disease

General: Fibroids are classified by where they grow in relation to the uterus. There are subserosal fibroids (outside the uterus), intramural fibroids (in the middle of the uterus), and submucosal fibroids (inside of the uterus, near the endometrial lining). Peduncles are stalks that can grow on the surface of the uterus, and they can develop fibroids themselves known as pedunculated fibroids. Pedunculated fibroids are sometimes a subclassification of subserosal or submucosal fibroids, but some doctors classify them as in their own group. A woman can have one type of fibroid, a couple of types, or all the types of fibroids.
Subserosal fibroids: These fibroids grow on the outside of the uterus and, as they grow, they expand further out into the uterine cavity. Subserosal fibroids generally have no effect on menstrual flow, but they may cause lower back pain, pelvic pain, increased urination, and constipation if they push onto the surrounding tissues/organs. Subserosal fibroids account for about 20% of all fibroid cases.
Intramural fibroids: In this type, the fibroids grow from within the uterine wall and they expand inward, causing the uterus to bulge. A doctor may suspect intramural fibroids if the uterus feels larger than normal during an examination. Intramural fibroids are the most common, accounting for about 70% of all fibroid cases, and they can potentially cause any of the symptoms associated with fibroids.
Submucosal fibroids: Fibroids that grow just under the inner lining of the uterine cavity (called the endometrial lining) are called submucosal fibroids. They are the least common type of fibroid, accounting for only 5% of all cases. But even a small submucosal fibroid may cause symptoms of heavy bleeding and prolonged menstrual periods.
Pedunculated fibroids: Peduncles are stalk-like growths on the inside or the outside of the uterus where a fibroid can grow and hang off. When a fibroid grows on a peduncle, it is called a pedunculated fibroid. If the fibroid is growing on the inside of the uterus, it is considered a pendunculated submucosal fibroid. If it is growing on the outside of the uterus, it is a pendunculated subserosal fibroid. The stalks on pedunculated fibroids have the ability to twist, which may cause severe or chronic pain or pressure on surrounding tissues.