Endometriosis is a condition in which endometrial cells (the cells that form the tissue that lines the uterus [endometrium]) grow in locations outside the uterus. This condition can cause severe pain and damage organs, frequently the reproductive organs.

Endometrial tissue growth is stimulated by the production of hormones throughout a woman’s menstrual cycle. The hormone estrogen causes the lining of the uterus to thicken and develop as it prepares to serve as the source of nutrition for a newly fertilized egg. When pregnancy does not occur, the endometrium is shed and leaves the body during menstruation.

When the endometrial tissue develops outside of the uterus, it grows in response to hormone stimulation as well, but cannot be shed. It attaches to organs, such as the ovaries and fallopian tubes, and can create pain, adhesions and scarring.

Endometriosis usually occurs during a woman’s reproductive years (ages 15 to 44). It is one of the leading causes of female infertility.

The cause of endometriosis is unknown. It is not completely understood if the endometrial tissue moves to other locations from the uterus or develops there as a result of cell changes. Women at higher risk for endometriosis include those who have never given birth, those who have had female surgical procedures and those with menstrual periods that last longer than eight days.

Some women experience chronic  pain with endometriosis while others experience little or no discomfort. The most common symptoms of endometriosis include:

• Pain during menstruation  (dysmenorrhea)
  
  
• Pain during sexual intercourse (dyspareunia)
  
  
• Painful urination (dysuria) or painful bowel movements (dyschezia) during menstruation
  
  
• Heavy menstrual bleeding or any premenstrual bleeding

Endometriosis is typically diagnosed by a gynecologist (GYN) by examination with a laparoscope, a viewing device inserted through an incision in the abdomen. In some cases, a biopsy may be performed of tissue. At the time of the laparoscopy, a physician determines the stage of endometriosis and discusses treatment options with the woman.

Treatment for endometriosis can be medical or surgical, depending on a woman’s age, symptoms and whether or not she plans to become pregnant. Medical treatments affect the hormonal cycles and may limit the growth of endometriosis. They include prescribing birth control pills or other hormones such as progesterone or gonadotrophin releasing hormone (GnRH). Medical treatments cannot reverse any damage caused by endometrial growths. Surgery is the only way to remove the growths.

Conservative surgery attempts to remove only the growths so a woman may still become pregnant. If it is unsuccessful, the physician may need to perform a hysterectomy (surgical removal of the uterus) and remove the ovaries and fallopian tubes. Hysterectomy is considered a treatment of last resort for women in their reproductive years. It is likely to end the symptoms, but also ends the opportunity for pregnancy. Women who have hysterectomies with removal of the ovaries (oophorectomy) reach menopause immediately and may experience related problems (e.g., hot flashes, night sweats, insomnia, osteoporosis). This surgical menopause usually causes more severe symptoms than those from natural menopause.

Even after medical treatments and conservative surgery, many women experience a return of some symptoms and more endometrial growths. It is believed that when a woman reaches menopause, most symptoms gradually lessen and the growths shrink, although studies have not confirmed this theory.

Endometriosis should not be confused with several other diseases of the endometrium, including endometrial cancer and endometritis. Adenomyosis (formerly known as endometriosis interna) is an endometrial condition where the endometrial lining grows deeper into the uterine wall. Formerly classified as a type of endometriosis, adenomyosis is now recognized as a separate and unrelated disease.