A normal size uterus lies below the pubic bone, well down in the pelvis. It is just under the bladder, just above the rectum, and surrounded by the intestines. Since it is so near to these other organs, growth of the uterus from fibroids may cause pressure or, rarely, pain in the pelvis. The uterus is normally about the size of a small pear and weighs less than one-quarter of a pound. But with fibroids, the uterus will enlarge and can cause an awareness of fullness or pressure. If the fibroids grow toward your back, pressure on the rectum can cause constipation. You may also feel pressure or pain in the lower back or discomfort with activity or intercourse. If the fibroids grow towards the front of the uterus, they can press on the bladder and cause frequent urination. However, fibroids do not cause any permanent damage to any of the organs.

Sudden Pain
Fibroids are living tissue, and need blood and oxygen to survive. If a fibroid grows quickly, blood vessels feeding the fibroid may not be able to grow fast enough to supply the new tissue with enough blood and oxygen. If this happens, the fibroid undergoes a process called degeneration, or cell death. As the cells in the fibroid die, chemical substances are released that cause pain and swelling in the uterus. This pain may be severe but is not usually associated with any serious problems.
If you have a degenerating fibroid, a heating pad on your abdomen will be comforting, and pain medication should provide relief for a few days or weeks until the pain begins to subside.

Urinary Problems
The uterus lies directly beneath the bladder, and the uterus and bladder are partially attached at one point. If a fibroid begins to grow forward, it may squeeze the bladder so that it cannot fill properly with urine and you may feel the need to urinate more often. Also, when you laugh, cough, or sneeze, the fibroid may push against the bladder and cause you to lose urine. This is called stress incontinence. While this may only be a minor inconvenience for some women with fibroids, others may be so bothered by the incontinence that they limit their activity to avoid embarrassment. There are also other causes of incontinence, so you should get a careful examination.

Fertility Problems
Fibroids that change the shape of the uterine cavity or are within the cavity decrease fertility by about 70% and removal of these fibroids increases fertility by 70%. Other types of fibroids, those that are within the wall but do not change the shape of the cavity, or those that bulge outside the wall do not decrease fertility, and removal of these types of fibroids does not increase fertility.

Miscarriage
Fibroids that bulge into the uterine cavity or are within the cavity may sometimes cause miscarriages. The fertilized egg comes down the fallopian tube and takes hold in the lining of the uterus. If a submucosal fibroid happens to be nearby, it can thin out the lining and decreases the blood supply to the developing embryo. The fibroid may also cause some inflammation in the lining directly above it. The fetus cannot develop properly, and miscarriage may result. However, with the next pregnancy, it is possible that the egg will settle in another location, and pregnancy may proceed without problems. However, if you do have a miscarriage and a fibroid is found bulging into the uterine cavity, it is advisable to have it removed.

Treatment
When is treatment necessary for fibroids?

Fibroids that do not cause symptoms, are small, or occur in a woman who is nearing menopause often do not require treatment. Certain signs and symptoms may signal the need for treatment:

Medications to treat fibroids
Drug therapy is an option for some women with fibroids. Medications may reduce the heavy bleeding and painful periods that fibroids sometimes cause. They may not prevent the growth of fibroids. Surgery often is needed later. Drug treatment for fibroids includes the following options:

Birth control pills and other types of hormonal birth control methods—These drugs often are used to control heavy bleeding and painful periods.

Gonadotropin-releasing hormone (GnRH) agonists—These drugs stop the menstrual cycle and can shrink fibroids. They are sometimes used before surgery to reduce the risk of bleeding. Because GnRH agonists have many side effects, they are used only for short periods (less than 6 months). After a woman stops taking a GnRH agonist, her fibroids usually return to their previous size.

Progestin–releasing intrauterine device—This option is for women with fibroids that do not distort the inside of the uterus. It reduces heavy and painful bleeding but does not treat the fibroids themselves.