Dysfunctional Uterine Bleeding


What Is It?

Dysfunctional uterine bleeding, also called anovulatory bleeding, is any bleeding from the vagina that varies from a woman’s normal menstrual cycle. The normal cycle is triggered by signals from hormones. Dysfunctional uterine bleeding occurs when the cycle’s hormonal signaling gets thrown off. It can include alternating heavy and light periods or spotting, or unpredictable shorter and longer cycles.

The regular monthly menstrual cycle flushes out the endometrial lining, the blood-enriched layer of tissue that grows inside the uterus every month in anticipation of a possible pregnancy.

If ovulation does not occur, periods can be delayed, which allows the endometrial lining to grow thicker. For that reason a delayed period is often a heavy one.

Lighter periods or spotting between periods may represent leakage from an endometrial lining that is unstable, either because hormonal levels don’t adequately support it or because the lining may be too thick.

Other factors that can change bleeding patterns include:

  • Certain hormonal abnormalities (thyroid problems, hyperprolactinemia)
  • Medications
  • Excessive exercise or weight loss
  • Stress or illness
  • The start of menstruation in adolescence — Regular ovulatory cycles may not develop for a few months or even years.
  • The end of menstruation — Dysfunctional uterine bleeding is also common in the months to years before menopause.


Irregular bleeding can come at different times from month to month and last for different amounts of time. The amount of flow also may vary from light or scant to extremely heavy with large clots.


Your doctor will ask about your medical history and about symptoms that might suggest a cause for the irregular bleeding or other hormonal abnormalities. The doctor may perform various tests to rule out these causes of the abnormal bleeding patterns:

  • Pregnancy — Urine or blood tests
  • Thyroid hormone and prolactin hormone abnormalities — Blood tests
  • Menopause (especially in a woman in her 40s or 50s) — Blood tests to determine if estrogen levels are falling, which suggests of the beginning stages of menopause
  • Abnormalities of the uterus or ovaries — A transvaginal ultrasound, in which a small, rodlike probe is inserted into the vagina to take specific measurements of the endometrial lining
  • The possibility of cancer in a woman over the age of 35; or women who have previously had breast, ovarian or colon cancer; have a strong family history of these cancers; or who has not had a period in six months — An endometrial biopsy, done in the office, in which the doctor uses a speculum to look at the cervix, then inserts a thin, strawlike tube through the cervix into the uterus and brushes it along the endometrial layer to collect a tissue sample

If you are having heavy bleeding, your doctor also will check the iron levels in your blood to see if you are anemic.

Expected Duration

Most women have a period that is irregular in timing or amount of bleeding at some point during their menstrual years, most often because of a cycle without a normal ovulation. Normal periods may resume as early as the next period or might take a few months to become regular. Some women become regular only with the help of treatments such as the birth-control pill. If the irregularity signals the beginning of menopause, the last period may not occur for a few months or a few years.


There is no way to prevent dysfunctional uterine bleeding, but see a doctor promptly if you have persistently irregular periods. Early diagnosis and treatment can help to make your periods regular again, which is important for your overall health.


If the cause of dysfunctional uterine bleeding is related to another medical condition, treatment of the condition should restore normal ovulatory cycles. Otherwise, treatment is based on the cause of the bleeding and the amount of bleeding.

Birth-control pills, which combine estrogen and progesterone, can regulate and decrease the amount of bleeding. Your doctor may recommend that you take monthly pills containing progesterone only.

Heavy bleeding can be stopped with higher doses of hormone pills — either estrogen or progesterone. When bleeding is more severe, hospitalization may be necessary. If hormonal therapy does not work, a surgical D and C (dilation and curettage) can stop severe cases of bleeding. During this procedure, the tissue lining of the uterus is physically withdrawn, allowing a healthier lining to take its place.

If an endometrial biopsy finds endometrial hyperplasia — a thicker, more developed and hormone-stimulated lining — closer monitoring with treatment may be required, especially in older women and postmenopausal women on hormone replacement therapy. Endometrial hyperplasia increases a woman’s risk of developing endometrial cancer.

When To Call A Professional

You should call your doctor for an evaluation right away if you are having fevers, abdominal pain or heavy bleeding with symptoms of dizziness or fainting.

If your periods are irregular over a few months, you should make an appointment to see your doctor for further evaluation. Be prepared to tell your doctor the dates of your last few periods.


There are many effective treatments to help regulate periods and control irregular bleeding. If you have irregular periods and are having difficulty conceiving, your fertility can be improved with drugs that stimulate ovulation. Having anovulatory or irregular menses, however, does not mean you are infertile, and you still need protection against pregnancy when you are sexually active.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.