Endometriosis is caused by the growth of uterine lining tissue outside the uterus. It can cause severe pain and infertility. Learn more about the condition, its diagnosis and the different treatment options available.



Endometriosis is a non-contagious gynecological condition that happens when tissue that normally lines the uterus – the endometrium – grows outside the uterus. Every month this endometrial tissue responds to the menstrual cycle and breaks down and bleeds.

Endometriosis can involve a number of different organs:

  • the fallopian tubes,
  • the ovaries,
  • on and behind the lower part of the uterus,
  • on the ligaments that keep the uterus in place,
  • on the intestine, kidneys and bladder,
  • on the peritoneum.

In rare cases, endometriosis can spread outside the pelvic area. This displaced tissue develops into growths (or lesions) which break down and bleed each month in response to the menstrual cycle. The result is inflammation which creates cysts, scar tissue and adhesions between pelvic tissue and organs.


Symptoms and impact on health

Depending on the location, the symptoms of endometriosis are varied. They can be chronic or periodic, and some women have no symptoms at all. The severity of the symptoms is not necessarily an indicator of the seriousness of the lesions.

The most common symptoms are:

  • gynecological pain before and during periods, and in ovulation (40% of women with the condition): painful periods, pain during intercourse, pelvic pain, pain with bowel movements, pain during urination, lower back, or abdominal pain;
  • premenstrual bleeding;
  • infertility (30 to 40% of women with endometriosis);
  • diarrhea or constipation;
  • digestive upsets;
  • tiredness.
  • Pain, which is mild at first and then intensifies, and becomes cyclical.


Risk factors

There are no known reasons why some women develop endometriosis. One possible explanation is an immune system disorder or that genetic factors are involved.



Endometriosis affects approximately 10% of women of childbearing age, or 176 million women around the world.


of women worldwide have endometriosis.

30 to 40%

of women with endometriosis have difficulty getting pregnant and need IVF.

Last update 13/04/2017