Endometriosis is a chronic inflammatory condition in which endometrial-like tissue (glandular epithelium and stroma) implants and grows outside the uterine cavity, most commonly on the ovaries, fallopian tubes, uterosacral ligaments, pelvic peritoneum, and rectovaginal septum. The ectopic endometrial tissue responds to cyclic estrogen and progesterone stimulation, undergoing proliferation, secretion, and bleeding with each menstrual cycle, but the blood and debris cannot be expelled from the body, causing local inflammation, fibrosis, and adhesion formation. Retrograde menstruation (Sampson's theory) is the most widely accepted pathogenic mechanism, though immune dysfunction (impaired clearance of ectopic tissue by NK cells and macrophages), coelomic metaplasia, and stem cell recruitment also contribute. Endometriotic lesions produce pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha), angiogenic factors (VEGF), and their own estrogen (via aromatase expression), creating a self-perpetuating inflammatory microenvironment. Clinical features include dysmenorrhea (cyclical pelvic pain), dyspareunia, dyschezia (painful bowel movements), chronic pelvic pain, and infertility. The nurse assesses pain using validated tools, administers prescribed hormonal therapy (combined oral contraceptives, progestins, GnRH agonists, aromatase inhibitors) to suppress estrogen and reduce endometrial proliferation, manages post-surgical care following laparoscopic excision, monitors for treatment...