What is endometriosis

WHAT IS
ENDOMETRIOSIS

An estimated 1 in 10 women of reproductive age have endometriosis

Where endometriosis occurs

Endometriosis is a chronic and painful disease that is more common than you might think. Here’s a quick refresher on the inner workings of endometriosis.

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Endometriosis is different for every woman.

The location of lesions can affect symptoms, but the extent of the disease doesn't necessarily relate directly to the level of pain experienced.

Endometriosis lesions are most commonly found in the pelvic area on organs like:

  • Ovaries
  • Fallopian tubes
  • Bladder
  • Bowels
  • Intestines
  • Rectovaginal septum (structure separating vagina and the rectum)
  • Peritoneum (membrane that forms the lining of the abdominal cavity)
Endometriosis lesions are most commonly found on organs in the pelvic area.

What causes endometriosis

Though the exact cause of endometriosis is unknown, most scientists think it relates to a process called retrograde menstruation. That’s when tissue that lines the inside of your uterus flows out in the wrong direction—through your fallopian tubes—during your period. The out-of-place tissue can cause pain and inflammation as it starts growing on surfaces and organs in your pelvic region.

There are other possible theories as to what can cause endometriosis, such as:

  • The immune system not destroying endometrium cells outside of the uterus the way it should
  • Metaplasia—where normal cells in the pelvic area change into endometrial cells
  • Endometrial cells forming outside of the uterus before birth. During puberty, these cells form endometrial lesions

Some lesions can even form their own nerves or scar tissue (called adhesions) between organs, which can cause pain. Although rare, lesions are sometimes found in areas further away from the pelvic area.

Levels of endometriosis

Endometriosis is sometimes categorized into 4 stages (from 1, which is minimal, to 4, which is severe). Each stage is based on location, amount, depth, and size of lesions. The pain associated with endometriosis may not be related to the stage of the disease. For example, a woman with Stage 1 of endometriosis could have significant pain or very mild pain.