Skip Navigation
NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health

Feature:
Endometriosis

What Is Endometriosis?

A problem common in women, endometriosis affects an estimated 5 million in the United States alone. The condition affects a woman’s uterus—the place where a baby grows during pregnancy.

The tissue that normally lines the inside of the uterus grows outside the uterus, causing pain, infertility, and very heavy periods. While the pain is usually in the abdomen, lower back, or pelvic areas, some women have no symptoms. For them, having trouble getting pregnant may be the first sign.

The cause of endometriosis is not known. Pain medicines and hormones often help. Severe cases may need surgery. There are also treatments to improve fertility in women with endometriosis.

Researchers used to think that patches growing outside the uterus caused the pain. In fact, the size and location of these patches are not related to the severity of pain or to the location of the pain.

What causes endometriosis?

The exact cause of endometriosis is not known, but researchers have some theories:

  • Genes are most likely involved to some degree, because the condition runs in families,
  • Estrogen (a hormone involved in the female reproductive cycle) also likely contributes to it, because it is an estrogen-dependent, inflammatory disease.
  • Progesterone resistance may be the cause. This is where the mucus membrane lining the uterus doesn't respond as it should to progesterone, another hormone involved in the female reproductive cycle.
  • Immune system dysfunction plays a role in some cases, where the immune system fails to destroy endometrial tissue, which enables it to grow outside the uterus.
  • Environmental exposures in the womb, such as to chemicals like dioxin, may also cause the condition.

What are the risk factors of endometriosis?

Studies show that women are at higher risk for endometriosis if their:

  • Mother, sister, or daughter had endometriosis (raises the risk about six times)
  • Periods started at an early age (before age 11)
  • Monthly cycles are short (less than 27 days)
  • Menstrual cycles are heavy and last more than 7 days

What are the symptoms of endometriosis?

While the primary symptoms of endometriosis are pain and infertility, other common symptoms include:

  • Painful, even debilitating, menstrual cramps, which may get worse over time
  • Pain during or after sex
  • Pain in the intestine or lower abdomen
  • Painful bowel movements or painful urination during menstrual periods
  • Heavy menstrual periods
  • Premenstrual spotting or bleeding between periods

What are the treatments for endometriosis?

Treatments for endometriosis pain fall into three general categories:

  • Pain medications
  • Hormone therapy
  • Surgical treatment

Research shows that some surgical treatments can provide significant, although short-term, pain relief from endometriosis.

Treatments for infertility related to the condition include in vitro fertilization (IVF), which makes it possible to combine sperm and eggs in a laboratory to make an embryo. The resulting embryos are placed into the woman's uterus.

Not all treatments work well for all women with the condition. Similarly, there is always the chance that the symptoms may return after the treatment is stopped.

For more information on treatment options, visit:
NIH's endometriosis treatment page.

Endometriosis: A Personal Story

Finding Relief After Diagnosis and Treatment

Melissa McGaughey
Photo courtesty of: Melissa McGaughey

Melissa McGaughey, a 36-year-old grant writer in Milwaukee, Wis., began her journey with endometriosis when she was only 13.

“Throughout high school and college, my pain got worse,” says McGaughey, who had pain throughout her pelvic region that extended through her thighs all the way to her knees. She stayed home often and had to drag herself to school, unable to participate in gym or hang out with friends because she was in so much pain.

The Diagnosis

The condition is often difficult to diagnose, and it can be challenging for young patients to decide whether to get a diagnostic surgery which might find no endometriosis. “My OB-GYN told me pretty early on that endometriosis might be the reason for my pain, but years passed before I was ready to move forward with surgery. I hope the next generation doesn’t require surgery for a diagnosis,” says McGaughey, who underwent diagnostic surgery soon after graduating from college.

The first procedure helped, but she had surgery a second time because the severe pain eventually returned. “The surgeon who did my first procedure had done some of these procedures, but wasn’t a specialist in endometriosis,” she says. “I’ve since learned that you can get better outcomes from surgeons who specialize in endometriosis.”

Managing Symptoms

While she still has pain, McGaughey has less pain since her surgeries. She’s been able to get pregnant after struggling with infertility, and now has a two-year-old daughter. “I’ve been helped by taking a strong anti-inflammatory medicine several days a month,” says McGaughey, who has also tried acupuncture, xi gong (a form of meditative exercise), continuous birth control pills, and diet changes to control her symptoms.

McGaughey suggests finding a doctor who specializes in endometriosis if you’re experiencing symptoms.

“It’s important to do your own research and be your own advocate,” McGaughey advises. “Be brave in talking about it. Too many women and girls feel they can’t say it out loud. It’s not a secret. We need to take girls’ pain seriously!”

Read More "Endometriosis" Articles

Confronting Endometriosis / What Is Endometriosis? / NIH Seeks Answers for Endometriosis

Summer 2016 Issue: Volume 11 Number 2 Page 10-11