List three causes of secondary amenorrhea in women under 40.

List three causes of secondary amenorrhea in women under 40.

• A. POI, hypothalamic dysfunction, hyperprolactinemia
• B. Pregnancy-related
• C. Endometriosis, fibroids, PCOS
• D. Natural aging, menopause, midlife exhaustion

Answer: (A)

Secondary amenorrhea in women under 40 most often reflects disruptions in the hypothalamic–pituitary–ovarian axis. The three commonly tested etiologies are premature ovarian insufficiency, hypothalamic dysfunction, and hyperprolactinemia. Premature ovarian insufficiency means the ovaries stop functioning earlier than normal, reducing estrogen production and halting menses; it presents with ongoing amenorrhea and typically shows elevated FSH with low estradiol on testing. Hypothalamic dysfunction, often called functional hypothalamic amenorrhea, arises from factors such as energy deficit, stress, or excessive exercise, which suppress GnRH pulses and downstream LH/FSH and estrogen; this form is usually reversible when the underlying stressor is addressed. Hyperprolactinemia raises prolactin levels that dampen GnRH secretion, preventing ovulation and causing amenorrhea; it can result from medications, pituitary tumors, or other causes and is diagnosed by elevated prolactin levels with or without galactorrhea. Pregnancy must be considered and ruled out early in the evaluation, but among nonpregnant causes in this age group, these three are the most important to recognize and differentiate because they guide targeted testing and management.

Secondary amenorrhea in women under 40 most often reflects disruptions in the hypothalamic–pituitary–ovarian axis. The three commonly tested etiologies are premature ovarian insufficiency, hypothalamic dysfunction, and hyperprolactinemia. Premature ovarian insufficiency means the ovaries stop functioning earlier than normal, reducing estrogen production and halting menses; it presents with ongoing amenorrhea and typically shows elevated FSH with low estradiol on testing. Hypothalamic dysfunction, often called functional hypothalamic amenorrhea, arises from factors such as energy deficit, stress, or excessive exercise, which suppress GnRH pulses and downstream LH/FSH and estrogen; this form is usually reversible when the underlying stressor is addressed. Hyperprolactinemia raises prolactin levels that dampen GnRH secretion, preventing ovulation and causing amenorrhea; it can result from medications, pituitary tumors, or other causes and is diagnosed by elevated prolactin levels with or without galactorrhea.

Pregnancy must be considered and ruled out early in the evaluation, but among nonpregnant causes in this age group, these three are the most important to recognize and differentiate because they guide targeted testing and management.