Endometriosis

Endometriosis is a disease in which tissue similar to the endometrium, the lining of the uterus, grows in other places in the body, outside the uterus. It occurs in women and a limited number of other female mammals. Endometrial tissue most often grows on or around reproductive organs such as the ovaries and fallopian tubes, on the outside surface of the uterus, or the tissues surrounding the uterus and the ovaries (peritoneum). It can also grow on other organs in the pelvic region like the bowels, stomach, bladder, or the cervix. Rarely, it can also occur in other parts of the body.

Symptoms can be very different from person to person, varying in range and intensity. About 25% of individuals have no symptoms, while for some it can be a debilitating disease. Common symptoms include pelvic pain, heavy and painful periods, pain with bowel movements, painful urination, pain during sexual intercourse and infertility. Nearly half of those affected have chronic pelvic pain, while 70% feel pain during menstruation. Up to half of affected individuals are infertile. Besides physical symptoms, endometriosis can affect a person's mental health and social life.

Diagnosis is usually based on symptoms and medical imaging; however, a definitive diagnosis is made through laparoscopy excision for biopsy. Other causes of similar symptoms include pelvic inflammatory disease, irritable bowel syndrome, interstitial cystitis, and fibromyalgia. Endometriosis is often misdiagnosed and many patients report being incorrectly told their symptoms are trivial or normal. Patients with endometriosis see an average of seven physicians before receiving a correct diagnosis, with an average delay of 6.7 years between the onset of symptoms and surgically obtained biopsies for diagnosing the condition.

Worldwide, around 10% of the female population of reproductive age (190 million women) are affected by endometriosis. Ethnic differences have been observed in endometriosis, as Southeast Asian and East Asian women are significantly more likely than White women to be diagnosed with endometriosis.

The exact cause of endometriosis is not known. Possible causes include problems with menstrual period flow, genetic factors, hormones, and problems with the immune system. Endometriosis is associated with elevated levels of the female sex hormone estrogen, as well as estrogen receptor sensitivity. Estrogen exposure worsens the inflammatory symptoms of endometriosis by stimulating an immune response.

While there is no cure for endometriosis, several treatments may improve symptoms. 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. Taking the active component of the birth control pill continuously or using an intrauterine device with progestogen may also be useful. Gonadotropin-releasing hormone agonist (GnRH agonist) may improve the ability of those who are infertile to conceive. Surgical removal of endometriosis may be used to treat those whose symptoms are not manageable with other treatments. Surgeons use ablation or excision to remove endometriosis lesions. Excision is the most complete treatment for endometriosis, as it involves cutting out the lesions, as opposed to ablation, which is the burning of the lesions, which leaves no samples for biopsy to confirm endometriosis.