The simple idea (no memorising)
PCOS (polycystic ovary syndrome) has a self‑feeding engine. Here's the loop:
Notice how it ties back to earlier concepts: high androgen (Concept 6) + no ovulation (Concept 14) + unopposed estrogen (Concept 14). PCOS is those threads woven together.
How doctors diagnose it: 2 out of 3
The Rotterdam criteria — you need any 2 of these 3, after ruling out look‑alikes:
- Hyperandrogenism — either visible (hirsutism, acne) or on a blood test.
- Ovulatory dysfunction — irregular or absent cycles.
- Polycystic ovary appearance on ultrasound (or a high AMH level in adults).
The trap to avoid
Many women have that ovary appearance without the syndrome. PCOS needs 2 of the 3, plus excluding mimics. It is a whole‑picture diagnosis, not a single scan.
It's a whole‑body syndrome
PCOS reaches beyond periods — it's linked with insulin resistance, weight changes, higher diabetes risk, and effects on mood and quality of life. A velvety darkening of skin folds (neck, armpits) called acanthosis nigricans is a visible flag of insulin resistance.
Why it matters
Seeing PCOS as a reproductive‑metabolic syndrome — not just an ovary problem — changes everything about how it's managed, which is the next concept.
Quick check ✅
- What are the three Rotterdam features — and how many do you need?
- Why is "polycystic ovaries on scan" alone not enough to diagnose PCOS?
Remember this 🌟
Where we're going next → If PCOS is a whole‑body syndrome, how do we help someone live well with it? Concept 18.