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Endometriosis: The 4 Stages & Treatment Options

Endometriosis illustration

Endometriosis is a common and often distressing condition for women. It occurs when the lining of the uterus — called the endometrium — grows in areas outside the uterus. Endometriosis is most commonly found in the ovaries, fallopian tubes, behind the uterus and on the outer surfaces of the uterus.

As many as one in 10 women of childbearing age have endometriosis, according to the American College of Obstetricians and Gynecologists (ACOG). The condition causes pain and can lead to difficulty getting pregnant.

When endometrial tissue is found in other areas of the body, it's called an endometriosis implant, notes the American Society of Reproductive Medicine (ASRM). These implants can be just small, flat patches, or they can invade tissue and grow into masses called nodes. Endometriosis on or in the ovary can develop into a blood-filled cyst, called chocolate cysts because of their brownish-reddish color. These cysts are a concern because if they break apart, they can spread endometriosis farther into the pelvic cavity and cause significant pain.

The stages of endometriosis

There are four stages of endometriosis, and most women have minimal or mild endometriosis, corresponding to stages 1 or 2, the ASRM says. Determination of the stage is based on the location of the implants, how deep the implants are, whether there are adhesions, how severe adhesions are, whether there are ovarian endometriomas (chocolate cysts), and the size of any ovarian endometriomas, says ASRM.

Unlike other conditions with staging, such as cancer, endometriosis stages have no impact on life expectancy. Endometriosis stages also don't necessarily match the types of symptoms you're having. For example, you might have stage 3 endometriosis, but little pain. Meanwhile, someone with stage 1 endometriosis might experience severe pain, explains the Endometriosis Foundation of America (EFA).

The stages are:

  • Stage 1: Someone with stage 1 endometriosis has only minimal disease. It includes only a few endometriosis implants, and they aren't deep in the body's tissues.
  • Stage 2: This stage is classified as mild disease. There are more implants, and they are implanted deeper in the tissue.
  • Stage 3: ASRM describes this stage as moderate disease. A woman will have numerous deep implants and small cysts on her ovaries, possibly chocolate cysts. There may also be scar tissue that binds organs, known as filmy adhesions."
  • Stage 4: This stage indicates severe disease. There will be many deep implants, as well as large cysts on one or both ovaries. Scar tissue will have formed dense adhesions. Infertility is more likely with this stage of endometriosis.

The ASRM isn't the only group with a classification system for endometriosis. The EFA has a system that grades endometriosis in categories that indicate where the endometrial tissue has traveled. Separating endometriosis into categories based on location might help better identify the type of treatment needed, the EFA says.

Its categories include:

  • Category 1: This type of endometriosis is mild. It typically has spread only to the lining of the abdomen (peritoneum).
  • Category 2: This means that the endometriosis has invaded the ovaries and caused chocolate cysts.
  • Category 3: This category represents the first level of deeply penetrating endometriosis. It may involve organs in the pelvic cavity, like the ovaries, rectum and uterus.
  • Category 4: Invasive endometriosis can affect organs all over, such as the bowels, the appendix, diaphragm, lungs and heart. It's even possible for the brain to be affected.

How does endometriosis feel?

Many women don't know they have endometriosis. It often doesn't cause any obvious symptoms

Among women who do have symptoms, pain is a likely symptom. Women may feel pain:

  • During menstruation as very painful menstrual cramps
  • During sex
  • In the lower back and pelvic area for long periods
  • During bowel movements
  • While urinating during a menstrual period

Women may also have:

  • Bleeding between periods
  • Digestive issues, such as diarrhea, constipation and nausea
  • Infertility. About 40 percent of women who have trouble getting pregnant have endometriosis.

Diagnosing endometriosis

A doctor may suspect endometriosis if a woman has very painful periods, or if she is having pain during sex. A doctor may also look for endometriosis if a woman is having trouble getting pregnant. To diagnose endometriosis, you may have:

  • A physical exam. During a pelvic and rectal exam, your doctor can feel large cysts or scar tissue. If you have smaller areas of scar tissue or small cysts, your doctor probably won't be able to feel them.
  • An ultrasound. You may have an abdominal or transvaginal ultrasound. During an abdominal ultrasound, a technician will run a small device over your abdomen. A transvaginal ultrasound uses a wand-shaped scanner inserted into your vagina. This test can identify ovarian cysts.
  • Other imaging tests. Both magnetic resonance imaging (MRI) and computed tomography (CT scan) can also be used to find ovarian cysts.
  • Diagnostic surgery. A minimally-invasive surgery called laparoscopy is the only definitive test for endometriosis. This procedure lets doctors look for endometriosis tissue in your pelvic area. A small sample of tissue (biopsy) can also be taken during the surgery so it can be tested later. Some treatments can also be done during laparoscopy.

Treatment options for endometriosis

There is no one treatment for endometriosis, and unfortunately, no cure for the condition, either. The treatments you'll be offered will depend on your symptoms and whether you'd still like to become pregnant. Treatment options include:

  • Over-the-counter pain relievers. Anti-inflammatory medications such as ibuprofen (Advil, Motrin) or naproxen (Aleve) can help relieve endometriosis pain.
  • Lifestyle changes. If you have pain during sex, changing positions may help. Exercise and relaxation techniques may also help ease pain from endometriosis.
  • Alternative medicine therapies. Women may get symptom relief with a variety of treatments, including acupuncture, chiropractic adjustments, herbs and dietary supplements, according to the U.S. Office on Women's Health.
  • Hormone therapy. Birth control pills and other types of hormone therapy can be helpful in women who don't already have severe pain. Treatment with hormones doesn't cause existing endometriosis tissue to go away. However, hormone therapy may slow new tissue from growing. This can reduce pain symptoms.
  • Surgery. If hormones don't help, you have severe pain or you're having trouble getting pregnant, surgery may be an option. During a surgical procedure, the endometriosis tissue that's implanted and cysts can be removed. Many women feel better after surgery, but endometriosis tissue can come back. ACOG estimates that 40 to 80 percent of women have pain again within two years of having surgery. Hormone therapy can help keep women pain-free for longer after surgery.
  • Hysterectomy. If women aren't planning on any additional pregnancies, a hysterectomy — removal of the uterus — is another surgical option. This is often thought of as a last-resort option for women having severe symptoms. ASRM says that hysterectomy could provide relief for up to 90 percent of women.

Treatment effects on fertility

Medications used to treat endometriosis don't seem to boost a woman's odds of pregnancy. Surgery to remove endometriosis implants and cysts does seem to improve the chances of pregnancy slightly. Women older than 35 may want to consider using fertility-enhancing treatments to increase their odds of getting pregnant.

A lifelong concern

Because there's no cure, endometriosis is a lifelong condition that can impact your quality of life. Work with a specialist who is familiar with the latest treatments in endometriosis so you can get recommendations that would be best for you.

Article references

  1. American College of Obstetricians and Gynecologists, Endometriosis -
  2. American Society for Reproductive Medicine, Endometriosis -
  3. Endometriosis Foundation of America, Endometriosis Stages: Understanding the Different Stages of Endometriosis -
  4. U.S. Office on Women's Health, Endometriosis -