What is endometriosis?

Endometriosis is a common and often painful chronic condition in reproductive-aged people. It is simply defined as the presence of endometrial tissue (tissue that forms the lining of the uterus) outside of the uterus, particularly on the ovaries and in the lower pelvis. Between 25 and 50 percent of women with infertility are estimated to have endometriosis.

What causes endometriosis?

There are several theories as to the cause of endometriosis, but none has been established with certainty. The three principal theories include:

  • Retrograde menstruation through the fallopian tubes leading to abnormal implantation of endometrial tissue in the pelvis
  • Spread of endometrial tissue in the blood vessels and lymphatics
  • Coelomic metaplasia or the ability of cells in the pelvic cavity to develop into endometrial tissue

Endometriosis tends to be seen most commonly in those who have a long duration of uninterrupted menstrual cycles, including those who have never been pregnant, those with an early onset of their menstrual cycle, and those with menopause at a late age. Endometriosis is seen less frequently in people who have interruptions in their menstrual cycle, such as those with multiple pregnancies and long periods of breastfeeding.

Endometriosis does have a genetic component as well. Those with first-degree family members diagnosed with endometriosis have a seven percent likelihood of developing the disease compared to a one percent chance without a family history. 

What are the symptoms of endometriosis?

Endometriosis may be associated with:

  • Excessive menstrual cramps and pain during menstrual periods
  • Heavy menstrual flow
  • Pelvic pain including during intercourse
  • Infertility
  • Painful urination and bowel movements during menstrual periods
  • Gastrointestinal distress including constipation, diarrhea, and nausea

The symptoms of endometriosis tend to worsen over time, although some people with endometriosis may not experience symptoms at all.

How is endometriosis diagnosed?

The definitive diagnosis of endometriosis requires surgical biopsy or clear laparoscopically visible pelvic lesions. The presence of an endometrioma (ovarian cyst of endometriosis) on a pelvic sonogram can help in establishing a strong clinical diagnosis.

How is endometriosis treated?

There are both medical and surgical options for the treatment of endometriosis. Medical treatment options relieve pain associated with endometriosis but only suppress and do not eliminate the disease. There is no evidence to suggest that medical treatment improves fertility.

Medical therapy includes hormonal treatments like birth control pills, and anti-inflammatory medications like over-the-counter pain killers that can be used separately or in combination.

Surgical treatment of endometriosis is recommended to restore normal pelvic anatomy that is often altered by resultant adhesive disease and to ablate or excise as much visible endometriosis as possible. Surgery is also suggested for the removal of endometriomas, especially once these cysts are greater than 2 cm.