Match the following with its most likely cause of amenorrhea: 33 y/o g1p1 with amenorrhea and ...
1. infertility and hot flashes
2. marathon runner
3. acne and coarse hair on chin

A. PCOS
B. hypothalamic hypogonadism
C. primary ovarian insufficiency

First, what is amenorrhea?
The absence of menstruation; missing three menstrual periods in a row 

Primary ovarian insufficiency: cessation of ovarian function <40 y/o
↑GnRH↑FSH↓Estrogen
*Buzz words: "menopause symptoms" i.e. hot flashes

Polycystic Ovarian Syndrome (PCOS): exact pathophysiology unknown; excess androgens, estrogen, and increased LH:FSH
↑GnRH (nl) FSH↑Estrogen
*Buzz words: facial hair, acne, obesity, diabetes

Hypothalamic hypogonadism: low GnRH; possibly from things such as insufficient caloric intake
↓GnRH↓FSH ↓Estrogen  
*Buzz words: runner, dancer, low BMI, thin, diet Infertility & hot flashes

Answers:
1. Primary Ovarian Insufficiency & infertility + hot flashes
2. Hypothalamic Hypogonadism & marathon runner
3. PCOS & acne and coarse hair on chin
primary ovarian insuffiCIency

**We don't love endorsing patient stereotypes! These are exam patterns that students will see and this is just some of the science behind them.