Secondary amenorrhea, within gynecologic endocrinology, is defined as absence of menses for three cycle lengths or three to six months in a person who has previously menstruated, distinguishing it from primary amenorrhea (never having menstruated). Its causes are organized mechanistically by the hypothalamic-pituitary-ovarian axis, classified according to whether follicle-stimulating hormone (FSH) is low/normal (hypothalamic-pituitary dysfunction, chronic anovulation, or other endocrine disease) or high (ovarian failure/insufficiency), with additional categories for anatomic causes (intrauterine adhesions obstructing outflow) and hyperandrogenic states. This etiologic framework, combined with a stepwise diagnostic algorithm (history/physical, pregnancy exclusion, FSH/estradiol/prolactin testing), links a specific hormonal or anatomic derangement to a discrete underlying diagnosis.
Secondary amenorrhea, within gynecologic endocrinology, is defined as absence of menses for three cycle lengths or three to six months in a person who has previously menstruated, distinguishing it fr…