What is the diagnostic work-up for amenorrhoea?

1. Pregnancy test first (exclude pregnancy)
2. History and examination - secondary sexual characteristics, weight/exercise/stress, virilisation, galactorrhoea, anosmia
3. Hormones - FSH/LH (high = ovarian failure; low = hypothalamic/pituitary), prolactin, thyroid function, testosterone (if hyperandrogenism)
4. Imaging - pelvic ultrasound (uterus/ovaries), and karyotype or pituitary MRI as indicated

Clinical relevance. A structured work-up (pregnancy test, FSH/LH, prolactin, thyroid, ultrasound) localises the cause of amenorrhoea and directs treatment.

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Diagnostic work-up for amenorrhoea

A structured work-up localises the cause along the reproductive axis.

Step 1 - exclude pregnancy

• A pregnancy test is always first (the commonest cause of secondary amenorrhoea).

Step 2 - history and examination

• Assess secondary sexual characteristics (primary amenorrhoea), weight/exercise/stress and eating, galactorrhoea, virilisation/hirsutism, anosmia (Kallmann's), visual fields, and a genital examination (outflow obstruction, blind vagina).

Step 3 - hormonal tests

• FSH/LH - high = ovarian failure (POI/Turner); low/normal = hypothalamic or pituitary cause.
• Prolactin (hyperprolactinaemia), thyroid function.
• Testosterone/androgens if hyperandrogenism (PCOS, tumours, CAH).
• Oestradiol; progesterone challenge in some.

Step 4 - imaging/genetics

• Pelvic ultrasound - uterus present/absent, ovarian morphology (PCOS), outflow.
• Karyotype (primary amenorrhoea with ovarian failure - Turner; or suspected AIS).
• Pituitary MRI - if hyperprolactinaemia or a pituitary lesion is suspected.