Abnormal Uterine Bleeding

Once menstruation starts, most women have regular cycles. They know when to expect bleeding, and when it should end. But some women struggle with irregularity, or unusual bleeding during or in between their periods.

This is called abnormal uterine bleeding. It is described as bleeding that’s heavy, lasts a long time, or happens between periods.

Abnormal uterine bleeding can be caused by common hormone problems. One hormone problem is called anovulation. This is when an ovary does not produce an egg during a menstrual cycle. This happens in many women one or two times each year. It can be more common in perimenopause. This is a long period of hormone changes leading up to menopause.

Another hormone problem is polycystic ovarian syndrome, also known as PCOS. This is a complex condition that leads to irregular periods, cysts on the ovaries, excess hair growth, and other symptoms.

In some cases, abnormal uterine bleeding can be caused by growths such as polyps or fibroids. It may be caused by cancer of the uterus or cervix, or tumors that are not cancer.

It can also be caused by pregnancy, miscarriage, and infections or other problems with the uterus.


Symptoms of abnormal uterine bleeding can occur in many ways. Bleeding may last from one period to the next. It may be a constant flow. Or it may be a very light flow known as spotting. Bleeding may occur for a few days, stop for a few days, and then start again. It may last for a few weeks and then stop. It may be very heavy and cause clots.


To find out why you have abnormal uterine bleeding, your healthcare provider may perform a pelvic exam. You may also have an imaging test, such as an ultrasound, which uses sound waves to create images of your pelvic organs. Or, your provider may place a thin tool called a hysteroscope into your vagina and through the cervix. This lets your healthcare provider see inside the uterus. Another possible test is called an endometrial biopsy. During this test, a small piece of the lining of the uterus is taken and sent to a lab. You may have a pregnancy test or a pap test. You may also have a blood test to check your hormone levels or blood counts.


If the bleeding is very heavy, treatment may be needed to stop blood loss. In most cases, this can be done with a hormone medication. Severe blood loss can cause anemia, which is often treated with iron supplements.

If the bleeding is caused by growths, these may be removed. In some cases, your provider may recommend a procedure called an endometrial ablation. This procedure treats the inside lining of the uterus to stop the bleeding. In rare cases, the uterus may need to be removed to stop symptoms. This is called a hysterectomy.

Your healthcare provider will discuss your treatment options with you.

What to Do

Tell your healthcare provider if there is a chance you may be pregnant. Keep track of your menstrual cycle and let your provider know about any changes.

Take your medication exactly as directed. Don't stop taking it when the bleeding stops, unless your health care provider tells you to.

Call your healthcare provider if your symptoms do not go away, or if they get worse. Let your provider know if you feel dizzy, weak, or short of breath. These may be symptoms of severe anemia. Call if your bleeding is soaking through pads or tampons every 2 hours, or if you have large blood clots.

What We Have Learned

  1. Abnormal uterine bleeding is caused by having sex during your period. True or False?
    The answer is False. Some causes of abnormal uterine bleeding are hormones, polycystic ovary disease, growths like fibroids, and even cancer.
  2. Ultrasound is one way to find out what’s causing abnormal uterine bleeding. True or False?
    The answer is True. Your healthcare provider may use ultrasound, a hysteroscope, or take some tissue for a biopsy to find out what’s causing the problem.
  3. Endometrial ablation is one treatment for abnormal uterine bleeding. True or False?
    The answer is True. This procedure treats the inside lining of the uterus to stop the bleeding.