Endometriosis is a painful condition caused by the growth of the endometrium — tissue that normally lines the inside of the uterus — in other parts of the body. Endometrium can grow in the

  • ovaries
  • outer surface of the uterus
  • fallopian tubes
  • ligaments that support the uterus
  • bladder

Abnormal endometrial tissue acts just like normal endometrial tissue. With each menstrual cycle, it thickens, breaks down, and bleeds. The surrounding tissue can become irritated and may even develop scar tissue.

Endometriosis can also cause large, blood filled cysts on the ovaries. These are called chocolate cysts because of their dark color.

Experts aren't sure what causes endometriosis. There are many theories. A leading one is called retrograde menstrual flow: blood and tissue that normally leaves the body during a woman's periods instead move into the pelvis. It's also possible that the immune system or hormonal problems play a role. Because endometriosis tends to run in families, there may be a genetic component as well.

Symptoms of endometriosis

Pain is the most common symptom of endometriosis. It can appear as:

  • painful periods that may become increasingly uncomfortable over time
  • persistent (chronic) pain in the lower back or pelvis
  • pelvic pain during or after sex
  • painful bowel movements or urination during menstrual periods.

Other symptoms include bleeding between periods and unexplained digestive problems such as diarrhea, constipation, bloating, or upset stomach, especially during menstrual periods.

Some women with endometriosis get pregnant with no trouble. Yet nearly half of all women who have trouble getting pregnant have endometriosis.

Endometriosis often gets better after menopause when there is a drop-off in the body's production of reproductive hormones. But because the body still produces small amounts of estrogen, some women continue to have symptoms even after menopause.

Diagnosing endometriosis

A woman's symptoms, including the location of her pain and when it occurs, is a key piece of information in diagnosing endometriosis.

Several tests may be done to check for endometriosis. These include:

  • a pelvic exam
  • an ultrasound exam
  • laparoscopy

Laparoscopy is the best way to diagnose endometriosis. During this procedure, a doctor uses a laparoscope, a slim instrument with a light and a camera, to view the organs in the pelvis. Sometimes endometriosis can be recognized simply by how the tissue looks. Other times the doctor must take a sample of tissue and send it to a lab for evaluation.

Treating endometriosis

There are two basic goals in treating endometriosis: relieving and preventing pain, and treating endometriosis-related infertility for women who wish to become pregnant.

For women with mild symptoms, taking an over-the-counter pain reliever may be all that's need. Choices include nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen. Prescription pain medication may also be an option.

Another way to stop the pain of endometriosis is by controlling estrogen and other hormones that fuel the growth or activity of endometrial tissue. Lifestyle changes such as regular exercise and limiting alcohol and caffeine can help rein in estrogen levels. Hormonal methods such as taking birth-control pills or other hormonal treatments delivered by pill, shot, or nasal spray, can ease symptoms. However, symptoms usually return when you stop taking these medications.

Surgery to remove areas of endometriosis can provide significant pain relief, but the results may be temporary because each menstrual cycle gives endometriosis an opportunity to come back.

All treatment options have risks and side effects. The right choice for you will depend on several things, including your age, how bad your symptoms are, and whether you're planning to become pregnant in the near future.

For women with endometriosis-related infertility, surgery to remove areas of endometriosis may improve the chances of becoming pregnant. If this is not successful, assisted reproduction with in vitro fertilization is often the next step.