Causes of gynecologic bleeding include:

Anovulation is a common cause of gynecological hemorrhage. Under the influence of estrogen the endometrium (uterine lining) is stimulated and eventually such lining will be shed off (estrogen breakthrough bleeding). The anovulation chapter discusses its multiple possible causes. longstanding anovulation can also lead to endometrial hyperplasia and facilitate the development of endometrial cancer.

1. Cancer of the uterus is always a concern, specifically when the bleeding occurs after menopause. Other types of cancer include cervical cancer; bleeding in that case can sometimes be triggered by intercourse and is termed postcoital bleeding. Cancers of the vagina or fallopian tubes are rare causes of hemorrhage.
2. Uterine fibroids represent a common, benign condition that may lead to bleeding, specifically if the lesion affects the uterine cavity.
3. Polyps of the uterine lining are a common cause of bleeding, but such bleeding tends to be light.

1. Sexual assault and rape can lead to injury and gynecological hemorrhage.
2. Trauma to the lower abdomen may lead to internal or external bleeding.

Women with a bleeding disorder may be prone to more excessive bleeding. A hematologic work-up should discover the cause.

On occasion an ovarian cyst can rupture and give rise to internal hemorrhage. This may occur during ovulation or as a result of endometriosis.

If the pregnancy test is positive, consider pregnancy related bleeding (see obstetrical hemorrhage), including miscarriage and ectopic pregnancy.