What Is Abnormal Uterine Bleeding?

Abnormal uterine bleeding (AUB) is the name doctors use to describe when something isn't quite right with a girl's periods. Doctors also sometimes call AUB "dysfunctional uterine bleeding" (DUB). Like lots of medical names, it can sound worse than it is. Most of the time, AUB isn't something to worry about.

Abnormal uterine bleeding means that periods may be heavier or last longer than normal or not come at all. Bleeding between periods is also a sign of AUB. AUB isn't usually a major problem, but it can lead some girls to develop anemia (fewer red blood cells than normal).

If a girl has AUB, it might mean her periods last longer or have more bleeding than normal. Or, it might mean the opposite — that her bleeding is light and her periods aren't coming as often as they should.

Because AUB isn't usually a problem, doctors often don't do anything about it. But sometimes they take action if a medical condition is causing AUB. Doctors also might treat AUB if it is causing another problem. For example, doctors may worry that a girl could get anemia if she is bleeding more than she should.

What Causes Abnormal Uterine Bleeding?

Most of the time, AUB happens because of changes in the body's hormone levels.

For teen girls, one of the most common causes of hormone changes is when the body doesn't release an egg from one of the ovaries. This is called anovulation .

The release of an egg is part of the menstrual cycle. If a girl's body doesn't release an egg, the hormone changes can lead to less frequent or heavy periods.

Anovulation is most likely to happen after a girl first starts getting her period. That's because the signals from the brain to the ovaries aren't fully developed yet. It can last for several years until a girl's periods become regular.

Other things can lead a girl to develop AUB. Some illnesses (like thyroid disease or polycystic ovary syndrome) can mess with the body's hormones. Problems like compulsive exercise, not eating healthy foods, or too much stress can cause hormone changes. Some severe cases of AUB are caused by bleeding disorders such as von Willebrand disease.

What Are the Signs & Symptoms of Abnormal Uterine Bleeding?

Every woman has a heavy period from time to time. How do you know if it's abnormal uterine bleeding? Only a doctor can tell for sure, but there are some signs that bleeding might not be normal.

One thing that can alert you to problems is the 1-10-20 test:

  • You use more than 1 sanitary pad or tampon per hour.
  • Your period lasts more than 10 days.
  • There have been fewer than 20 days between your periods.

If you notice any of these things, call your doctor. Bleeding in between periods or after sex also can be a sign of AUB.

If your period stops for more than 3 months, ask your doctor about that too. If you're not bleeding, the lining of the uterus can keep building up. Eventually it will need to flow out.

How Is Abnormal Uterine Bleeding Diagnosed?

A doctor will want to rule out other health problems before deciding a girl has AUB. For example, doctors might find out that a girl with heavy periods has a bleeding disorder like von Willebrand disease.

To diagnose AUB, doctors will ask questions about periods and bleeding. Expect your doctor to ask the date your last period started.

A doctor also might ask questions that don't seem connected to bleeding — like about recent weight changes or if you have ever had sex. Doctors ask these questions because conditions like polycystic ovary syndrome and some STDs can cause abnormal bleeding. If they're not treated, they may lead to more serious health issues, like infertility (not being able to have a baby).

Girls who have had sex and miss a period need to see a doctor. Missed periods could be a sign of pregnancy as well as a sign of AUB. If you have heavy bleeding or bleeding between periods, it could be an infection or other problem. For example, an ectopic pregnancy (when a pregnancy implants someplace other than the uterus) can cause bleeding, and can be life-threatening.

A doctor might do a physical exam and maybe a pelvic exam. Sometimes doctors order blood tests or ultrasound exams. Blood tests also can show if a girl has anemia.

How Is Abnormal Uterine Bleeding Treated?

Doctors treat AUB based on what's causing it.

If a girl has very heavy bleeding, her doctor might test for anemia and prescribe iron pills or other treatments. For very light or irregular bleeding that goes on for a long time, medical professionals often prescribe birth control pills. Birth control pills contain hormones that can help balance a girl's menstrual cycle.

Most girls just need time for their bodies to adjust to their hormones. Eventually, their menstrual cycles get regular naturally. If you're ever worried that your period might not be normal, talk to your doctor.

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Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2020 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.

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