Endometriosis is a disease in which tissue that normally lines the uterus, called the endometrium, grows outside the uterus. This abnormal growth occurs in patches or nodules called endometrial lesions. These lesions usually develop in the pelvic cavity, on or under the ovaries, on the tubes connecting the ovaries to the uterus, behind the uterus, on the tissues that hold the uterus in place. They may also grow on the bowels or bladder, and in rare cases, in the lungs and elsewhere.

The primary symptoms of endometriosis are pain and infertility.

Pain as a symptom of endometriosis

Pain is the main symptom of endometriosis, but the severity of the pain a patient experiences does not seem to correlate with the size or number of endometriosis lesions; some women with few endometrial lesions have severe pain, while others with advanced stages of endometriosis — stage 3 or 4 — have relatively little pain. The pain usually gets worse during menstruation and may become more severe over time.

In addition to generalized pelvic pain, patients may also experience:

  • Painful, even debilitating, menstrual cramps
  • Pain during or after intercourse
  • Pain or pressure around the bladder
  • Painful bowel movements, especially during menstruation.

Causes of endometriosis pain 

The cause of pain in endometriosis is not well understood. Women with the disease usually report increased pain before or during a period. This is because endometrial lesions swell and shed, just like the normal endometrium, but because they cannot be expelled properly, they cause inflammation and pain. With time, the lesions may develop into a fibrous tissue scar, which can increase the pain a woman experiences and make it chronic.

Endometrial lesions can also form near a nerve, and either the lesion itself or the inflammation it causes puts pressure on the nerve to cause pain. 

Treatment of endometriosis-related pain

Endometriosis currently has no cure, but there are several treatments that can help ease the pain associated with this disease. Three types of treatment are commonly used to ease endometriosis pain: pain relief medication, hormonal therapy, and surgery.

For mild pain, non-steroidal anti-inflammatory drugs (NSAIDS), like acetaminophen, ibuprofen, and naproxen, are often prescribed. For severe pain, narcotic analgesics may be prescribed. Narcotic analgesics are strong pain relievers that act directly on the nervous system. Examples include hydrocodone, oxycodone, and hydromorphone.

Hormone treatment can come in the form of pills, injections, or intrauterine devices. These treatments are meant to stop the production of estrogen in the ovaries, preventing the menstrual cycle that is known to exacerbate pain in endometriosis patients.

There are also several experimental treatments that work to induce an artificial menopause to halt menstruation. These include Linzagolix and Relugolix.

Orilissa, approved by the U.S. Food and Drug Administration (FDA) in July 2018 to treat moderate to severe pain caused by endometriosis, acts through a similar mechanism. That is, Orilissa dampens the effects of the gonadotropin-releasing hormone (GnRH), a hormone produced in the brain that stimulates the production and secretion of ovarian hormones.

Typically, surgery is a last resort for treating the disease, and has been shown to lead to significant improvements in controlling endometriosis pain in the short-term. The most common surgical procedure for endometriosis is laparoscopy, a minimally invasive method to remove the lesions. Laparotomy has the same purpose, but it is a more extreme procedure for larger lesions, especially those that lie behind the uterus.


Endometriosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.