PCOS Diagnosis Guide: How to Get Diagnosed with PCOS in 2025

The Three Main PCOS Diagnosis Criteria

1. Irregular Cycles^{1 2}

• First day of one period to the first day of the next period is more than 35 days apart or less than 21 days apart
• Less than 8 menstrual cycles per year
• More than 90 days for any 1 menstrual cycle
• This only applies after 3 years of having your first period because irregular can be normal in this period

2. Hyperandrogenism^{2 3}

• Elevated male hormones like testosterone
• Hair loss (from scalp)
• Acne
• Hair growth on face, chest, back, lower abdomen, and/or thighs

3. Polycystic Ovaries^{1 2 3}

• At least 20 follicles measuring 2 mm to 9 mm in the ovary or increased ovarian size more than 10 ml
  • Cysts are immature follicles (normal to have in all ovaries)! The number of follicles is what indicates PCOS.
  • Historically, the threshold was 12 follicles, but as transvaginal ultrasonography has become more common (more accurate than transabdominal ultrasonography), the threshold has been updated to 20.

Blood Tests for PCOS Diagnosis

Testosterone and Androgen Testing

• Testosterone, androstenedione or LH, either alone or in combination, were raised in 86% of women with PCOS.⁴ In some women with PCOS, testosterone may be normal.
  • Total testosterone is likely to be more reliable than free testosterone given the difficulties seen with many of the assays used for the latter.⁵
  • Most testosterone values in PCOS will be ≤150 ng/dL (≤5.2 nmol/L).⁵
  • Total and free testosterone were significantly higher in the studied PCOS group (92.5 ±9.1 and 5.7 ±3.6, respectively) compared to controls (44.3 ±6.9 ng/dl and 2.5 ±2.8 pg/ml, respectively).⁶
  • At least 3 months off oral contraceptives is best to get a “true” testosterone value.⁵

LH/FSH Ratio Testing

• A luteinizing hormone/follicle stimulating hormone (LH/FSH) ratio of ≥2.0 has been used to suggest PCOS, but its use is controversial with some suggesting it should be abandoned because it is not highly sensitive or specific.^{4 5}

Anti-Müllerian Hormone (AMH) Testing

• Anti-Müllerian Hormone (AMH) levels can be used to aid in the diagnosis of PCOS in adults (should not be used for adolescents).⁷ Although the exact threshold value has not been established (they are assay and population-specific), AMH along with LH, and follicle count have demonstrated a high predictive value for diagnosing PCOS.⁸

All sources here are from peer-reviewed journals.

References

1. CMAJ – PCOS diagnostic criteria and clinical manifestations
2. Diagnostics – International evidence-based guideline for PCOS assessment
3. National Library of Medicine – Polycystic ovary syndrome comprehensive review
4. British Journal of Obstetrics and Gynaecology – Hormonal characteristics in PCOS women
5. Clinical Medicine & Research – Testosterone measurement and PCOS diagnosis
6. Menopause Review – Testosterone levels comparison in PCOS patients
7. The Journal of Clinical Endocrinology & Metabolism – 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome
8. Journal of Ovarian Research – AMH predictive value for PCOS diagnosis