Pathophysiology
Clinical meaning
Menopause management addresses the multisystem consequences of estrogen deficiency that follow permanent cessation of ovarian follicular function. The loss of circulating 17-beta estradiol affects virtually every organ system through tissue-specific estrogen receptor (ER-alpha and ER-beta) signaling. Vasomotor symptoms (hot flashes, night sweats) result from narrowing of the thermoneutral zone in the hypothalamus caused by estrogen withdrawal-induced dysfunction of KNDy (kisspeptin/neurokinin B/dynorphin) neurons, which normally modulate the thermoregulatory center โ small fluctuations in core body temperature that previously would not trigger a response now initiate inappropriate heat dissipation (cutaneous vasodilation, diaphoresis). Genitourinary syndrome of menopause (GSM) develops as estrogen-dependent vaginal epithelium loses its glycogen-rich stratified squamous architecture, becoming thin, pale, and less elastic with elevated pH (greater than 5.0), predisposing to dyspareunia, vaginal infections, and recurrent urinary tract infections. Bone resorption accelerates because estrogen normally suppresses RANKL expression on osteoblasts; without estrogen, RANKL binds RANK on osteoclast precursors, driving osteoclastogenesis and net bone loss of 2-3% per year in the first 5-7 years after menopause. Cardiovascular risk increases as estrogen withdrawal reduces nitric oxide-mediated vasodilation, shifts lipid profiles toward atherogenic patterns...