What is PCOD/PCOS?
PCOS (Polycystic Ovary Syndrome) is a hormonal disorder where the ovaries produce excess androgens (male hormones), causing irregular periods, excess facial/body hair (hirsutism), acne, hair thinning and difficulty conceiving. It is also strongly linked to insulin resistance, weight gain and long-term risk of Type 2 diabetes and heart disease. PCOD (Polycystic Ovarian Disease) is an older term often used interchangeably in India, though technically they're slightly different.
Blood Tests Used in PCOS Diagnosis
| Test | What it measures | Typical finding in PCOS |
|---|---|---|
| LH (Luteinising Hormone) | Ovulation trigger hormone | Elevated (LH:FSH ratio >2:1) |
| FSH (Follicle Stimulating Hormone) | Egg maturation hormone | Normal or low |
| LH:FSH Ratio | Balance of reproductive hormones | >2:1 or >3:1 suggests PCOS |
| Total Testosterone | Main male hormone | Elevated (above 0.6 ng/mL in women) |
| DHEA-S | Adrenal androgen | May be elevated |
| Prolactin | Milk hormone | Normal (rules out other causes) |
| AMH (Anti-Müllerian Hormone) | Ovarian reserve / follicle count | Elevated in PCOS |
| Fasting Insulin | Insulin resistance marker | Elevated (>15 µIU/mL fasting) |
| Fasting Blood Sugar / HbA1c | Diabetes/prediabetes screen | Often prediabetic |
| TSH (Thyroid) | Rules out thyroid as cause | Normal (to rule out hypothyroidism) |
What does a high LH:FSH ratio mean in PCOS?
LH:FSH ratio above 2:1
Normally LH and FSH are roughly equal (1:1). In PCOS, LH is persistently elevated relative to FSH, disrupting the normal ovulation cycle. This ratio is supportive of PCOS but not diagnostic on its own — it must be combined with symptoms and an ultrasound. Note: this ratio is less reliable if taken during the LH surge at mid-cycle.
What does high AMH mean?
AMH above 5 ng/mL — High ovarian reserve, PCOS marker
AMH (Anti-Müllerian Hormone) is produced by follicles in the ovaries. In PCOS, multiple small follicles are present (the "cysts"), causing AMH to be 2–3 times higher than normal. High AMH in the context of irregular periods and androgen excess strongly supports PCOS. AMH is now used as a more reliable marker than the LH:FSH ratio in many centres.
Questions to ask your doctor
- Do I have insulin resistance and should I start metformin?
- Do I need a pelvic ultrasound to count follicles?
- Is my PCOS affecting my fertility?
- What lifestyle changes will have the most impact on my hormone levels?