Abnormal uterine bleeding is abnormal bleeding resulting from changes in the hormonal control of menstruation.
Bleeding occurs frequently or irregularly, lasts longer, or is heavier.
This disorder is diagnosed when the physical examination, ultrasonography, and other tests have ruled out the usual causes of vaginal bleeding.
An endometrial biopsy is usually done.
The bleeding can usually be controlled with estrogen plus a progestin (a synthetic female hormone) or progesterone (similar to the hormone the body makes) or sometimes with one of these hormones alone.
If the biopsy detects abnormal cells, treatment involves high doses of a progestin and sometimes removal of the uterus.
Abnormal uterine bleeding (previously called dysfunctional uterine bleeding) occurs most commonly at the beginning and end of the reproductive years: 20% of cases occur in adolescent girls, and more than 50% occur in women older than 45.
In about 90% of cases, the ovaries do not regularly release an egg (ovulate). Thus, pregnancy is less likely. However, because the ovaries may occasionally release an egg, these women should use contraception if they do not wish to become pregnant.
Abnormal uterine bleeding commonly results when the level of estrogen remains high instead of decreasing as it normally does after an egg is released and is not fertilized. The high estrogen level is not balanced by an appropriate level of progesterone. In such cases, no egg is released, and the lining of the uterus (endometrium) may continue to thicken (instead of breaking down and being shed normally as a menstrual period). This abnormal thickening is called endometrial hyperplasia. Periodically, the thickened lining is shed incompletely and irregularly, causing bleeding. Bleeding is irregular, prolonged, and sometimes heavy.
If this cycle of abnormal thickening and irregular shedding continues, precancerous cells may develop, increasing the risk of cancer of the uterine lining (endometrial cancer), even in young women.
Abnormal uterine bleeding is often an early sign of menopause.