Abnormal Uterine Bleeding

By OBOS Common Medical Conditions Contributors |

Heavy menstrual bleeding (which may include clots of blood) or bleeding happening outside the normal cyclic menstruation is referred to as abnormal uterine bleeding (AUB). AUB is a common gynecological problem, but its causes can be tricky to diagnose. The most likely cause of AUB for any woman depends on whether she is premenopausal, perimenopausal (near menopause), or postmenopausal.

Some causes of AUB include hormonal imbalances, pregnancy, the use of hormonal contraceptives (birth control pills or Depo-Provera, for instance), fibroids, endometrial polyps, infection, and, more rarely, precancerous or cancerous growths. Infrequently, bleeding that seems to be coming from the vagina may actually come from the urinary tract or gastrointestinal tract. For severe bleeding without an obvious explanation, ask to be screened for von Willebrand disease, especially if you have a history of other bleeding problems.

Fibroids can cause heavy, longer periods, sometimes with cramping and clots. More commonly, this occurs when the fibroids are submucosal and impinge on the uterine lining. Such periods are usually not irregular. (For more information, see Fibroids.)

In addition to being a sign of a possible physical problem, heavy and/or irregular bleeding is a nuisance. It can also result in anemia from low iron and thus cause fatigue. Sometimes, heavy and prolonged bleeding may be part of the normal transition to menopause.

Abnormal Uterine Bleeding in Menstruating Women

If you are menstruating and notice any of the following patterns, contact your health care provider:

  • An episode of menstrual bleeding that lasts three or four days longer than usual
  • More than one menstrual cycle that is shorter than twenty or twenty-one days
  • Bleeding after intercourse
  • Heavy monthly bleeding, especially with clots (if you are soaking through ten sanitary products a day you are bleeding heavily)
  • Spotting or bleeding between menstrual periods

Abnormal Uterine Bleeding at Perimenopause

During perimenopause (the transition to menopause), new and different bleeding patterns are common. That makes it hard to decide when the menstrual cycle is normal and when there is a problem. The amount of blood flow may vary from month to month. Women sometimes skip their period for a few months, and then have regular periods again. However, if you are experiencing many episodes of irregular bleeding as described in the box above, it could be a sign of a medical problem that should be addressed.

Abnormal Uterine Bleeding in Menopausal Women

Women who take hormone therapy may experience normal or abnormal uterine bleeding. Your health care provider should explain the types of bleeding patterns to expect with your hormone prescription. If your bleeding is different from what you’ve been told to expect, contact your provider.

Vaginal bleeding is abnormal in any woman who is postmenopausal (has gone a full year without any menstrual periods), unless she is taking hormones.


Clinicians will review a woman’s medical history. For premenopausal women who are missing periods, the bleeding pattern may suggest pregnancy or ovulation (producing an egg). A pregnancy test can find out whether an abnormal pregnancy is causing AUB. Blood tests can check for anemia, thyroid function, and female hormone levels. Other symptoms, such as pelvic pain or hair growth, can suggest other particular causes of AUB.

A clinician may be able to detect uterine abnormalities such as fibroids through a pelvic exam. Women with AUB should get a Pap test if one has not been performed recently.

Adenomyosis (endometriosis in the wall of the uterus, a condition affecting about 10 percent of women) is another cause of heavy and painful periods. It can be diagnosed only with an MRI or a surgical specimen during a hysterectomy.

Four special tests are often used to evaluate AUB, as follows.

Endometrial biopsy: This is a quick office procedure involving the removal of tissue from the uterine lining (endometrium) to check for precancerous and cancerous cells. A thin tube, which is a suction device, is inserted into the uterus through the vagina and the cervical opening. It withdraws samples of uterine tissue for analysis. This may cause cramping, and some women will need pain medication, including anesthesia.

Transvaginal ultrasound: In this test, a wand placed in the vagina produces sound waves that create an image of the pelvic organs. The test can identify uterine fibroids. It measures the endometrial lining and may indicate abnormalities in the endometrium.

Sonohysterogram, or saline infusion sonography: This special kind of transvaginal ultrasound involves putting saline (salt water) into the uterus through a thin tube, to improve the image and detection of abnormalities.

Hysteroscopy: Diagnostic hysteroscopy involves threading a thin flexible scope into the uterus to view the contents of the uterine cavity. It can be done in the office or at a surgical procedure unit. Operative hysteroscopy is done at the hospital with anesthesia. A slightly larger scope is used to look at the uterine cavity and remove abnormal tissue such as fibroids or polyps.

Medical Treatments of Abnormal Uterine Bleeding

The treatment for abnormal bleeding depends on what is thought to be its cause. A woman’s age and plans for childbearing, as well as her preference, are important in planning the treatment. Treatments range from observation (and taking iron, if a woman is anemic) to hysterectomy, or removing the uterus.

Various medications can reduce or regulate abnormal bleeding and relieve pain. Nonsteroidal anti-inflammatory drugs (such as ibuprofen) taken for pain may also reduce bleeding. Tranexamic acid is a medication that significantly decreases menstrual bleeding. Only recently introduced in the United States, it has been available in other countries for many years. Birth control pills make the cycle more regular and reduce bleeding, but there is some controversy about using them during perimenopause (for more information, see the Centre for Menstrual Cycle and Ovulation Research).

An IUD (intrauterine device) treated with a progestin, such as the levonorgestrel-releasing Mirena, can be a nonestrogen hormonal option for controlling bleeding. Some other drugs, such as danazol and Lupron, reduce bleeding even more but also have serious negative side effects (see above); they are typically used for only a short time, to postpone or prepare you for surgery.

Noninvasive outpatient surgery (endometrial ablation) may be done with several techniques that cauterize, freeze, or remove the lining of the uterus to reduce bleeding. These include operative hysteroscopy (where the uterine lining is surgically removed) or the use of specially designed instruments such as the thermal balloon (ThermaChoice) or NovaSure to cauterize or even freeze the uterine lining. Endometrial ablation is an option after more serious causes of abnormal bleeding are ruled out. It may be less effective in the presence of fibroids. Hysterectomy is the only known effective treatment for adenomyosis.

Always discuss the particulars of your situation and your choices with your clinician. If you are uncomfortable with the options offered, try to get a second opinion.


If you are premenopausal, you may be able to stabilize your menstrual flow by reducing stress and changing your diet. Cutting down on animal fat and adding fiber helps to restore normal hormonal balance by lowering cholesterol, which is converted to estrogen in your body.

There is controversy about whether soy products—and which types—are beneficial for AUB or may help to regulate periods. Supplements of vitamins A, E, and C with bioflavonoids may help if your diet does not include enough of these vitamins. (Take no more than 10,000 IU of a vitamin A supplement twice a day, since larger doses can be toxic. One carrot contains 8,000 IU, and dark green leafy vegetables contain a lot, too, so you can get enough vitamin A from food.) If you are bleeding heavily, increase your iron intake to prevent anemia.

Some women find that Chinese medicine, including acupuncture and Chinese herbs, helps to restore hormonal balance. If you are approaching menopause, the bleeding may stop by itself as your hormone levels get lower.