Introduction May be primary or secondary primary absence of menses by age 16 secondary the absence of menses for three months in a woman with previous normal cycle most commonly due to unexpected pregnancy Causes hypothalamic dysfunction situational stress anorexia obesity serious illness excessive exercise excess cortisol, androgens, and prolactin malignancy pituitary dysfunction pituitary neoplasm prolactinoma hyperprolactinemia pituitary infarct Sheehan's syndrome ovarian failure menopause polycystic ovarian syndrome premature ovarian failure autoimmune destruction radiation chemotherapy endometriosis Turner syndrome end-organ imperforate hymen (primary amenorrhea) Rokitansky-Kuster-Hauser syndrome (primary amenorrhea) endometrial scarring (secondary amenorrhea) Asherman syndrome arises from intrauterine scarring following dilation and curettage most common anatomic cause Evaluation Hypothalamic/pituitary ↓ FSH and LH hypogonadotropic hypogonadism no menstrual bleeding when given progesterone Ovarian ↑ FSH and LH hypergonadotropic hypogonadism no menstrual bleeding when given progesterone End-organ normal FSH and LH normal estrogen and progesterone Treatment Hypothalamic/pituitary reverse underlying cause induce ovulation with gonadotropins excision if caused by tumor bromocriptine for prolactinoma Ovarian exogenous estrogen replacement End-organ surgery