Endometriosis, a debilitating condition affecting 6-10% of women of reproductive age, is characterized by the presence of endometrial glands and stroma in ectopic locations, primarily in the pelvic peritoneum, ovaries, and rectovaginal septum. The condition is associated with pelvic pain and infertility, and its pathogenesis remains multifaceted. Key theories include retrograde menstruation, where endometrial cells are displaced into the peritoneal cavity during menstruation, and the induction theory, which proposes that hormonal or immunologic factors promote the differentiation of peritoneal cells into endometrial cells. Other theories suggest that endometrial cells originate from bone marrow or other non-uterine tissues. The disease is characterized by genetic predisposition, estrogen dependence, progesterone resistance, and inflammation. Endometrial cells exhibit altered survival, proliferation, and invasion, and the development of endometriotic lesions is associated with neovascularization and increased cytokine production. Understanding these mechanisms is crucial for developing preventive strategies, non-surgical diagnostic methods, and effective treatments.Endometriosis, a debilitating condition affecting 6-10% of women of reproductive age, is characterized by the presence of endometrial glands and stroma in ectopic locations, primarily in the pelvic peritoneum, ovaries, and rectovaginal septum. The condition is associated with pelvic pain and infertility, and its pathogenesis remains multifaceted. Key theories include retrograde menstruation, where endometrial cells are displaced into the peritoneal cavity during menstruation, and the induction theory, which proposes that hormonal or immunologic factors promote the differentiation of peritoneal cells into endometrial cells. Other theories suggest that endometrial cells originate from bone marrow or other non-uterine tissues. The disease is characterized by genetic predisposition, estrogen dependence, progesterone resistance, and inflammation. Endometrial cells exhibit altered survival, proliferation, and invasion, and the development of endometriotic lesions is associated with neovascularization and increased cytokine production. Understanding these mechanisms is crucial for developing preventive strategies, non-surgical diagnostic methods, and effective treatments.