Endometriosis is a painful and often misunderstood condition that affects an estimated 1 in 10 women of reproductive age. It occurs when tissue similar to the uterine lining (endometrium) grows outside the uterus, leading to inflammation, scarring, and the formation of adhesions. This displaced tissue has estrogen receptors and responds to hormonal changes during the menstrual cycle, causing debilitating symptoms such as severe pelvic pain, heavy periods, digestive issues, and, in many cases, infertility.