Please note: This information was current at the time of publication. But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit, the AAFP patient education website.

Information from Your Family Doctor

Abnormal Bleeding During Your Period


Am Fam Physician. 2012 Jan 1;85(1):44.

  See related article on abnormal uterine bleeding.

How do I know if my periods are abnormal?

Periods are considered abnormal if they last more than seven days, have less than 24 days or more than 35 days between starting dates, or are very irregular or very heavy. Bleeding is considered very heavy if you have to change tampons or pads more than every one to two hours, or if you often pass clots larger than 1 inch. Vaginal bleeding in children or in women after menopause is always abnormal.

What causes abnormal periods?

Abnormal bleeding is common. Causes of irregular bleeding can include pregnancy, obesity, uncontrolled diabetes, thyroid problems, side effects from medicines, and cancer. Very heavy periods may be caused by thyroid problems, bleeding disorders, and noncancerous growths in your uterus. Many women have very heavy periods without a known cause.

Are they serious?

Abnormal bleeding can range from annoying to life-threatening, so talk to your doctor. He or she will ask you questions, do a physical exam, and perform other tests to try to find the cause. The most serious cause of abnormal bleeding is cancer.

What should I bring to my appointment?

Bring a list of all your medicines and supplements. Also bring a diary of your periods where you track the start and stop dates, how heavy the flow is, and any associated symptoms.

What kind of tests will I need to have?

First, you may need a pregnancy test and a blood test. The two other most useful tests are endometrial biopsy and transvaginal ultrasound. An endometrial biopsy is when your doctor takes a small sample of the lining of your uterus to look for cancer cells. A transvaginal ultrasound uses sound waves to make a picture of your ovaries and uterus so your doctor can look at them more closely.

How are abnormal periods treated?

It depends on the cause. Your doctor may recommend weight loss or anti-inflammatory medicines, such as ibuprofen (one brand: Motrin). He or she may prescribe hormonal medicines, such as birth control pills, or an intrauterine device (a device placed inside your uterus) to help decrease the bleeding. If these don’t help, you may need to see a gynecologist. Surgery may be needed to stop the bleeding.

This handout is provided to you by your family doctor and the American Academy of Family Physicians. Other health-related information is available from the AAFP online at

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.


Copyright © 2012 by the American Academy of Family Physicians.
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