Medically Reviewed by Jabeen Begum, MD on March 15, 2023
8 min read

Endometriosis happens when tissue that is similar to the tissue that lines your uterus grows outside of the uterus.

This tissue acts as regular uterine tissue does during your period: It will break apart and bleed at the end of the cycle. But this blood has nowhere to go. Surrounding areas may become inflamed or swollen. You might have scar tissue and lesions.

Endometriosis is most common in your ovaries.

Endometriosis is also grouped by what area of the pelvis or abdomen it affects. There are four main types:

  • Superficial peritoneal endometriosis. The peritoneum is a thin membrane that lines your abdomen and pelvis. It also covers most of the organs in these cavities. In this type, the endometrial tissue attaches to the peritoneum. This is the least severe form.
  • Endometriomas. These are dark, fluid-filled cysts. They’re also called chocolate cysts. They vary in size and can appear in different parts of your pelvis or abdomen, but they’re most common in the ovaries.
  • Deeply infiltrating endometriosis (DIE). In this type, the endometrial tissue has invaded the organs either within or outside your pelvic cavity. This can include your ovaries, rectum, bladder, and bowels. It’s rare, but sometimes a lot of scar tissue can bond organs so they become stuck in place. This condition is called a frozen pelvis. But this only happens to 1%-5% of people with endometriosis.
  • Abdominal wall endometriosis. In some cases, endometrial tissue can grow on the abdominal wall. The cells may attach to a surgical incision, like one from a C-section.

You might not notice any symptoms. When you have them, they can include:

  • Back pain during your period
  • Severe menstrual cramps
  • Pain when pooping or peeing, especially during your period
  • Unusual or heavy bleeding during periods
  • Blood in your stool or urine
  • Diarrhea or constipation
  • Painful sex
  • Fatigue that won’t go away
  • Trouble getting pregnant

Doctors don’t know exactly what causes endometriosis. Some experts think menstrual blood that contains endometrial cells may pass back through your fallopian tubes and into your pelvic cavity, where the cells stick to your organs. This is called retrograde menstruation.

Your genes could also play a role. If your mom or sister has endometriosis, you’re more likely to get it. Research shows that it tends to get worse from one generation to the next.

Some people with endometriosis also have immune system disorders. But doctors aren’t sure whether there’s a link.

Other reasons may include:

1) The transformation of peritoneal cells. Experts think that hormones or immune factors promote transformation of peritoneal cells — cells that line the inner side of your abdomen — into endometrial-like cells.

2) Embryonic cell transformation. Hormones such as estrogen may transform embryonic cells — cells in the earliest stages of development — into endometrial-like cell implants during puberty.

3) Surgical scar implantation. After a surgery, such as a hysterectomy or C-section, endometrial cells may attach to a surgical incision.

4) Endometrial cell transport. The blood vessels or tissue fluid (lymphatic) system may transport endometrial cells to other parts of the body.


Severe endometriosis pain can affect your quality of life. Some people struggle with anxiety or depression. Medical treatments and mental health care can help.

Endometriosis may raise your risk of ovarian cancer or another cancer called endometriosis-associated adenocarcinoma.

Endometriosis is the leading cause of infertility. It affects about 5 million people in the United States, many in their 30s and 40s. Nearly 2 of every 5 people who can’t get pregnant have it.

If endometriosis interferes with your reproductive organs, your ability to get pregnant can become an issue:

  • When endometrial tissue wraps around your ovaries, it can block your eggs from releasing.
  • The tissue can block sperm from making its way up your fallopian tubes.
  • It can stop a fertilized egg from sliding down your tubes to your uterus.

A surgeon can fix those problems, but endometriosis can make it hard for you to conceive in other ways:

  • It can change your body’s hormonal chemistry.
  • It can cause your body’s immune system to attack the embryo.
  • It can affect the layer of tissue lining your uterus where the egg implants itself.

Your doctor can surgically remove the endometrial tissue. This clears the way for the sperm to fertilize the egg.

If surgery isn’t an option, you might consider intrauterine insemination(IUI), which involves putting your partner’s sperm directly into your uterus.

Your doctor may suggest pairing IUI with “controlled ovarian hyperstimulation,” which means using medicine to help your ovaries put out more eggs. People who use this technique are more likely to conceive than those who don’t get help.

In vitro fertilization (IVF) is another option. It can raise your chances of conceiving, but the statistics on IVF pregnancies vary.

Your doctor might suspect endometriosis based on your symptoms. To confirm it, they can do tests including:

  • Pelvic exam. Your doctor might be able to feel cysts or scars behind your uterus.
  • Imaging tests. An ultrasound, a CT scan, or an MRI can make detailed pictures of your organs.
  • Laparoscopy. Your doctor makes a small cut in your belly and inserts a thin tube with a camera on the end (called a laparoscope). They can see where and how big the lesions are. This is usually the only way to be totally certain that you have endometriosis.
  • Biopsy. Your doctor takes a sample of tissue, often during a laparoscopy, and a specialist looks at it under a microscope to confirm the diagnosis.

There are different ways to measure endometriosis. The most widely used scale is from the American Society of Reproductive Medicine. Doctors assign points according to the spread of the endometrial tissue, its depth, and the areas of your body that are affected.

Based on the results, the condition is ranked in one of four stages:

  • Stage 1 or minimal: There are a few small implants or small wounds or lesions. They may be found on your organs or the tissue lining your pelvis or abdomen. There’s little to no scar tissue.
  • Stage 2 or mild: There are more implants than in stage 1. They’re also deeper in the tissue, and there may be some scar tissue.
  • Stage 3 or moderate: There are many deep implants. You may also have small cysts on one or both ovaries, and thick bands of scar tissue called adhesions.
  • Stage 4 or severe: This is the most widespread. You have many deep implants and thick adhesions. There are also large cysts on one or both ovaries.

Experts don’t know why some people have more severe cases than others. Endometriosis stages don’t take pain or symptoms into account. And it doesn’t always go from one stage to the next. If left untreated, it can remain the same over time. Or it may get worse or better.

If you’ve been diagnosed with endometriosis, you might want to ask things like:

  • Why is endometriosis painful?
  • What can I do to control my endometriosis symptoms?
  • Do I need medication? How does it work?
  • What are the side effects of medication for endometriosis?
  • Will endometriosis affect my sex life?
  • How do birth control pills affect endometriosis?
  • If I'm having trouble getting pregnant, could fertility treatments help? What about surgery?
  • Can surgery stop my symptoms?
  • What might happen if I do nothing? Can endometriosis go away without drugs or surgery?
  • Will it last my whole life?
  • Should I consider joining a clinical trial?
  • How often do I need to see a doctor?

There’s no cure for endometriosis. Treatments usually include surgery or medication. You might need to try different treatments to find what helps you feel better.

Pain medicine. Your doctor may recommend an over-the-counter pain reliever. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil, Motrin) or naproxen (Aleve) work for many people. If these don’t relieve your pain, ask about other options.

Hormones. Hormonal therapy lowers the amount of estrogen your body creates and can stop your period. This helps lesions bleed less so you don’t have as much inflammation, scarring, and cyst formation. Common hormones include:

  • Birth control pills, patches, and vaginal rings
  • Gonadotropin-releasing hormone (Gn-RH) agonists and antagonists such as elagolix sodium (Orilissa) or leuprolide (Lupron)
  • Progestin-only contraceptives
  • Danazol (Danocrine)

Surgery. Your doctor might recommend surgery to take out as much of the affected tissue as possible. In some cases, surgery helps symptoms and can make you more likely to get pregnant. Your doctor might use a laparoscope or do a standard surgery that uses larger cuts. Pain sometimes comes back after surgery.

In the most severe cases, you may need a surgery called a hysterectomy to take out your ovaries, uterus, and cervix. But without them, you can’t get pregnant later.

Warm baths, hot water bottles, and heating pads can give quick relief from endometriosis pain. Over time, lifestyle changes like these might also help:

Eat right. Research has shown a link between endometriosis and diets that are low in fruits and vegetables and high in red meat. Some experts think the high amount of fat in meat like beef encourages your body to produce chemicals called prostaglandins, which may lead to more estrogen production. This extra estrogen could be what causes excess endometrial tissue to grow.

Add more fresh fruits and vegetables by making them the heart of your meals. Stocking your refrigerator with pre-washed and cut fruit and vegetables can help you eat more of both.

Research has also found foods rich in omega-3 fatty acids, like salmon and walnuts, to be helpful. One study showed that women who ate the highest amount of omega-3 fatty acids were 22% less likely to develop endometriosis than the women who ate the least amount.

By comparison, those who ate the most trans fats had a 48% higher risk than those who ate the least, so the type of fat you eat matters.

Also, avoid alcohol and caffeine. Drinking caffeinated coffee and soda seems to increase your chances of developing endometriosis, although researchers aren’t sure why. Alcohol is also associated with a higher risk.

Exercise regularly. There are a lot of reasons exercise is a great way to manage your endometriosis. Working out encourages your heart to pump blood to all your organs, improve circulation, and help nutrients and oxygen flow to all your systems.

People who also exercise may have less estrogen and have lighter periods, which can help improve their symptoms of endometriosis over time. But there’s even more: Studies have shown that the more time you devote to high-intensity exercises like running or biking, the less likely you are to ever get endometriosis.

Exercise helps reduce stress. And because it releases brain chemicals called endorphins, it can actually relieve pain. Even just a few minutes of physical activity that makes you breathe hard or sweat can create that effect.

Lower-intensity workouts like yoga can be beneficial, too, by stretching the tissues and muscles in your pelvis for pain relief and stress reduction.

Manage stress. Researchers think stress can make endometriosis worse. In fact, the condition itself might be the cause of your stress because of the severe pain and other side effects.

Finding ways to manage stress -- whether it’s through yoga or meditation, or by simply carving out time for self-care -- can help you ease symptoms. It may also be helpful to see a therapist who can offer tips for dealing with stress.

Look at alternative therapies. Although there isn’t enough research that supports the use of alternative natural therapies for endometriosis, some people find relief from their symptoms through these techniques, including:

If you’re interested in trying an alternative therapy, be sure to talk to your doctor first, especially if you’re considering taking over-the-counter supplements. They could have side effects that you don’t know about. And never exceed the recommended dosage or take more than one supplement at a time.