Endometriosis (ENDO) is a disorder in which vascularized growths of endometrial tissue occur outside the uterus. Its symptoms include reduced fertility and severe pelvic pain. The main symptoms are pelvic pain and infertility. Pain during sex is also common. Infertility occurs in up to half of women affected. Less common symptoms include urinary or bowel symptoms. The cause is not entirely clear. Risk factors include having a family history of the condition. Most often the ovaries, fallopian tubes, and tissue around the uterus and ovaries are affected; however, in rare cases it may also occur in other parts of the body. Scientists use the rat model of endometriosis for studying the innervation of ectopic endometrium. Studies demonstrate that ectopic endometrial growths develop an autonomic and sensory innervation. This innervation could contribute not only to symptoms associated with ENDO but also to maintenance of the ectopic growths.
