The uterus, or womb, is the place where a baby grows when a person is pregnant. The uterus is lined with tissue (endometrium). Endometriosis is a disease in which tissue that is similar to the lining of the uterus grows in other places in your body. These patches of tissue are called "implants," "nodules," or "lesions." They are most often found:

• On or under the ovaries
• On the fallopian tubes, which carry egg cells from the ovaries to the uterus
• Behind the uterus
• On the tissues that hold the uterus in place
• On the bowels or bladder

In rare cases, the tissue may grow on your lungs or in other parts of your body.

The cause of endometriosis is unknown.

Endometriosis can affect anyone who menstruates. Certain factors can raise or lower your risk of getting it.

You are at higher risk if:

• You have a mother, sister, or daughter with endometriosis
• Your period started before age 11
• Your monthly cycles are short (less than 27 days)
• Your menstrual cycles are heavy and last more than 7 days

You have a lower risk if:

• You have been pregnant before
• Your periods started late in adolescence
• You breastfeed your babies

The main symptoms of endometriosis are:

• Pelvic pain, which often happens during your period.
• Infertility

Other possible symptoms include:

• Painful menstrual cramps, which may get worse over time
• Pain during or after sex
• Pain in the intestine or lower abdomen
• Pain with bowel movements or urination, usually during your period
• Heavy periods
• Spotting or bleeding between periods
• Digestive or gastrointestinal symptoms
• Fatigue or lack of energy

Surgery is the only way to know for sure that you have endometriosis. First, however, your health care provider will ask about your symptoms and medical history. You will have a pelvic exam and may have some imaging tests.

The most common surgery to diagnose endometriosis is a laparoscopy. This is a type of surgery that uses a laparoscope, a thin tube with a camera and light. The surgeon inserts the laparoscope through a small cut in the skin near your belly button. Your provider can make a diagnosis based on how the patches of endometriosis look. They may also do a biopsy to get a tissue sample.

There is no cure for endometriosis, but there are treatments for the symptoms. Your provider will work with you to decide which treatments would be best for you.

Treatments for endometriosis pain include:

• Pain relievers, including nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen and a prescription medicine specifically for endometriosis. Providers may sometimes prescribe opioids for severe pain.
• Hormone therapy, which stops the ovaries from making hormones. This may slow the growth of the endometrial tissue and may prevent new areas from growing. Types of hormone therapy include:
  • Birth control pills.
  • Progestin therapy.
  • Gonadotropin-releasing hormone (GnRH) medicines (GnRH agonists and antagonists). These medicines cause a temporary menopause. After your stop taking the medicines, your menstrual periods will start again, and pregnancy is possible.
• Surgical treatments for severe pain, including procedures to remove the endometriosis patches or cut some nerves in the pelvis. The surgery may be a laparoscopy or major surgery.

Treatments for infertility caused by endometriosis include:

• Laparoscopy to remove the endometriosis patches
• In vitro fertilization

NIH: National Institute of Child Health and Human Development