PCOS Symptom Checker: Rotterdam Criteria, Signs and the Path to Diagnosis
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age — and the most commonly missed. About 5–10 % of women are affected, yet many wait years for a diagnosis.
This article walks through the typical symptoms, the international Rotterdam criteria and the clear path to diagnosis — so you can step into a gynecology visit with a focused, evidence-backed suspicion.
The Rotterdam criteria (2 of 3 required)
Since 2003 the Rotterdam criteria (ESHRE/ASRM) have been the international gold standard for PCOS diagnosis. PCOS is met when two of these three are present:
1. Ovulatory dysfunction (oligo- or anovulation)
Cycles longer than 35 days, shorter than 21 days, or fewer than 8 menses per year.
2. Hyperandrogenism
Clinical (hirsutism, acne, androgenic alopecia) or biochemical (testosterone, free androgen index).
3. Polycystic ovaries on ultrasound
≥ 20 follicles per ovary or ovarian volume ≥ 10 mL — assessed by transvaginal ultrasound.
Important: other causes (hyperprolactinemia, thyroid disease, NCAH) must be ruled out first.
Typical symptoms — and what they mean
| Symptom | Background |
|---|---|
| Irregular cycles | Anovulation driven by disturbed LH/FSH regulation |
| Hirsutism | Elevated androgens, modified Ferriman-Gallwey ≥ 8 |
| Acne, oily skin | Sebum production driven by testosterone |
| Scalp hair thinning | Androgenic alopecia, classically a wider parting |
| Weight gain, central obesity | Insulin resistance and impaired glucose handling |
| Acanthosis nigricans | Dark velvety patches — direct skin marker of insulin resistance |
| Difficulty conceiving | Anovulation is the leading cause of infertility in PCOS |
Insulin resistance: the hidden driver
Up to 70 % of women with PCOS have insulin resistance — independent of body weight. High insulin amplifies ovarian androgen output and suppresses SHBG in the liver, increasing free testosterone. Acanthosis nigricans (dark velvety patches in skin folds) is the classic clinical clue.
A fasting insulin level or an oral glucose tolerance test belongs in any PCOS work-up. See the diabetes risk article — the metabolic link runs deep.
Run a PCOS symptom check
Score 9 typical signs along the Rotterdam criteria — with a clear next-step recommendation. Free, instant, no sign-up.
Start symptom check →The path to a diagnosis
- Cycle log over 3–6 months (period tracker app or basal body temperature).
- Hormone panel in the early follicular phase (day 2–5): testosterone, SHBG, free androgen index, DHEAS, LH/FSH, estradiol, prolactin, TSH, 17-OH-progesterone.
- Metabolic labs: fasting insulin, HbA1c, OGTT, lipid panel.
- Transvaginal ultrasound during the follicular phase for follicle count and ovarian volume.
- Rule out differentials: hyperprolactinemia, thyroid disease, non-classic adrenal hyperplasia, Cushing's.
What helps — therapy in a nutshell
Lifestyle
A 5–10 % weight loss often restores cycles in those with overweight and lowers androgens measurably. Strength training improves insulin sensitivity.
Medication
Metformin (insulin resistance), combined oral contraceptive (cycle, acne, hirsutism), spironolactone (antiandrogen), letrozole for ovulation induction.
Supplements
Inositol (myo / D-chiro 40:1) has improved cycles and ovulation in trials. Correct vitamin D deficiency where present.
Related calculators
PCOS sits at the intersection of cycle, ovulation and metabolic health. Track your cycle with the period calculator, plan ovulation, and check your diabetes risk — three numbers that together paint a clear picture of reproductive-metabolic health.
Bottom line
PCOS is a high-leverage diagnosis: once recognized, lifestyle and medication work well — cycles, skin, hair and fertility often improve substantially. The first step is taking the symptoms seriously. Start with the PCOS symptom checker and bring an evidence-based picture to your next appointment.