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Vaginal Bleeding (cont.)

Vaginal Bleeding Causes

Dysfunctional Uterine Bleeding

  • When bleeding is not caused by your menstrual cycle, it is called abnormal or dysfunctional uterine bleeding. This is the most common cause of abnormal vaginal bleeding during a woman's childbearing years. Up to 10% of women may experience excessive bleeding at one time or another. African American women tend to have more episodes.
  • When the complex hormonal processes of the menstrual cycle are interrupted, resulting in estrogen and progesterone levels that are out of balance, excessive vaginal bleeding may occur. This bleeding is related to irregularities of your menstrual cycle without any disease.
  • The diagnosis of dysfunctional uterine bleeding is a diagnosis of exclusion, which means that all other causes for the bleeding (including trauma, tumors, or diseases) have been considered and determined not to be the cause of the bleeding.
  • Depending on the female adolescent or woman's age, there are different reasons for the person to have dysfunctional uterine bleeding.
  • Dysfunctional uterine bleeding is commonly associated with an anovulatory cycle. Anovulation occurs when a menstrual cycle occurs that does not result in the release of an egg from one of the ovaries.
  • In some cases, dysfunctional uterine bleeding can occur with ovulation or the release of an egg from an ovary.
  • When a woman does not produce an egg, there is still stimulation of the uterus from the hormone estrogen. Progesterone, a very important hormone produced by the ovary after the release of an egg, is absent. Therefore, the lining of the uterus becomes unusually thick and enlarged.
  • Irregular shedding of the uterine lining and heavy bleeding occurs. The woman then experiences heavy, irregular vaginal bleeding (usually painless).

The most common cause of dysfunctional uterine bleeding in a female adolescent is anovulation.

  • In the first two years of a female adolescent having a menstrual cycle, 85% of the menstrual cycles can occur without the release of an egg.
  • As the female adolescent gets older, the percentage of cycles that are anovulatory decreases, and she is more likely to experience normal periods.
  • By the time the female adolescent has had a menstrual cycle for six years, fewer than 20% of cycles will occur without an egg being released from one of the ovaries.


In women of childbearing age (around 18-40 years), the most common cause of abnormal uterine bleeding is pregnancy and its complications, such as ectopic pregnancies or miscarriages. Anovulation can be a cause of bleeding in women of childbearing age. However, anovulation occurs in fewer than 20% of women in this category, so all other causes, including pelvic inflammatory disease and uterine fibroids, must be ruled out.


Older women who are approaching menopause may also experience dysfunctional bleeding due to the hormonal changes that accompany the menopausal transition.

Diseases of the female reproductive organs may cause bleeding.

  • A woman may have a harmless (not cancerous) sore (polyp or lesion) on her genitals that can cause bleeding.
  • Cancer of the vagina, cervix, uterus, and ovaries can cause bleeding. Ovarian cysts, cervicitis, endometritis, fibroids, vaginal infections, and other conditions can also cause excessive bleeding.
  • Vaginal bleeding is a particular concern in women older than age 50 years (or after menopause). The risk of cancer increases with age. Also, your vaginal walls may be dry from lack of estrogen, which may cause bleeding during or after sexual intercourse.

Certain drugs may cause bleeding, especially if a woman takes anticoagulant drugs (drugs that prevent the blood from clotting).

Inherited bleeding disorders (such as von Willebrand disease and hemophilia) may cause excessive or prolonged vaginal bleeding.

Trauma is also a cause of bleeding. Some IUDs may cause heavier periods (slight bleeding is usually normal; pay attention to heavier bleeding). Injury (trauma to the vaginal wall) from sexual intercourse may happen.

Medically Reviewed by a Doctor on 7/30/2015

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Dysfunctional Uterine Bleeding »

Dysfunctional uterine bleeding (DUB) is irregular uterine bleeding that occurs in the absence of pathology or medical illness.

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