Endometriosis is a condition in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside it.[6][7] Most often this is on the ovaries, fallopian tubes, and tissue around the uterus and ovaries; however, in rare cases it may also occur in other parts of the body.[2] The main symptoms are pelvic pain and infertility.[1] Nearly half of those affected have chronic pelvic pain, while in 70% pain occurs during menstruation.[1] Pain during sexual intercourse is also common.[1] Infertility occurs in up to half of women affected.[1] Less common symptoms include urinary or bowel symptoms.[1] About 25% of women have no symptoms.[1] Endometriosis can have both social and psychological effects.[8]
The cause is not entirely clear.[1] Risk factors include having a family history of the condition.[2] The areas of endometriosis bleed each month, resulting in inflammation and scarring.[1][2] The growths due to endometriosis are not cancer.[2] Diagnosis is usually based on symptoms in combination with medical imaging;[2] however, biopsy is the surest method of diagnosis.[2] Other causes of similar symptoms include pelvic inflammatory disease, irritable bowel syndrome, interstitial cystitis, and fibromyalgia.[1] Endometriosis is commonly misdiagnosed, and women are often incorrectly told their symptoms are trivial or normal.[8]
Tentative evidence suggests that the use of combined oral contraceptives reduces the risk of endometriosis. Exercise and avoiding large amounts of alcohol may also be preventive.[2] There is no cure for endometriosis, but a number of treatments may improve symptoms.[1] This may include pain medication, hormonal treatments or surgery. The recommended pain medication is usually a non-steroidal anti-inflammatory drug (NSAID), such as naproxen.[2] Taking the active component of the birth control pill continuously or using an intrauterine device with progestogen may also be useful.[2] Gonadotropin-releasing hormone agonist (GnRH agonist) may improve the ability of those who are infertile to get pregnant.[2] Surgical removal of endometriosis may be used to treat those whose symptoms are not manageable with other treatments.[2]
One estimate is that 10.8 million people are affected globally as of 2015.[4] Other sources estimate about 6–10% of women are affected.[1] Endometriosis is most common in those in their thirties and forties; however, it can begin in girls as early as eight years old.[2][3] It results in few deaths.[10] Endometriosis was first determined to be a separate condition in the 1920s.[11] Before that time, endometriosis and adenomyosis were considered together.[11] It is unclear who first described the disease.