> A note on the name: PCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) in May 2026 by global consensus. The condition, its diagnosis and its treatment are unchanged — only the name. Both terms will be in use for the next few years. We use PCOS below as the term most people recognise.
PCOS: symptoms and diagnosis
Why the name changed
The rename was not cosmetic. "Polycystic ovary" implies pathological cysts, which are not a feature of the condition — the ultrasound appearance reflects arrested follicular development, not cyst formation. The narrow ovarian focus of the old name is thought to have contributed to under-recognition: up to 70% of affected individuals remain undiagnosed.
Diagnosis: the Rotterdam criteria
Two of three:
- Irregular or absent ovulation
- Clinical or biochemical signs of raised androgens — acne, excess hair growth, or raised testosterone on testing
- Polycystic-appearing ovaries on ultrasound
An important update
Current international guidance accepts a raised AMH as an alternative to ultrasound for the ovarian criterion in adults. Useful where a transvaginal scan is not appropriate or not available.
Do not use ultrasound to diagnose adolescents
Ultrasound should not be used for the ovarian criterion within about eight years of a girl's first period. Multifollicular ovaries are normal at that age, and using the scan leads to over-diagnosis in adolescents.
PCOD versus PCOS
In everyday Indian use these are treated as the same. There is a real distinction:
PCOD usually refers to the ultrasound appearance alone. That appearance is common and, by itself, is not a diagnosis — a substantial proportion of women with no hormonal problem have polycystic-looking ovaries.
PCOS is the clinical syndrome diagnosed on the Rotterdam criteria. It carries metabolic implications that a scan appearance alone does not.
What else should be checked
Other conditions cause irregular cycles and get mistaken for PCOS — thyroid disorders, raised prolactin, premature ovarian insufficiency, and functional hypothalamic amenorrhoea.
That last one matters particularly: FHA is essentially the opposite situation, where cycles stop because energy availability is too low. The management is close to the reverse of PCOS advice, so getting this wrong has consequences.
The metabolic side
Insulin resistance with compensatory high insulin is present in 85% of those affected. It is one of three interacting disturbances the new name was chosen to reflect, alongside raised androgens and neuroendocrine changes.
Importantly, insulin resistance in PCOS is not explained by weight alone — lean women with PCOS can have it too, so testing should not be reserved for those who are overweight.
Ask about fasting glucose and HbA1c. PCOS carries a raised long-term risk of type 2 diabetes, and screening is often overlooked in younger women.
Long term
The reproductive symptoms often ease with age as androgen levels fall, and most resolve after menopause. The metabolic risks do not resolve on their own, and warrant periodic monitoring regardless of whether your periods are behaving.
Sources
- International Evidence-based Guideline for PMOS (formerly PCOS)
Frequently Asked Questions
Can you have PCOS with regular periods?▾
Yes. Phenotype C (ovulatory PCOS) is characterised by regular cycles combined with hyperandrogenism and polycystic ovaries on ultrasound — but without ovulatory dysfunction. This is the most commonly missed phenotype. Women with Phenotype C have fewer fertility problems but still have elevated androgen levels and metabolic risks that need monitoring.
What is the Rotterdam criteria for PCOS diagnosis?▾
Per Rotterdam 2023 criteria, PCOS requires any 2 of: (1) ovulatory dysfunction (irregular/absent cycles, <8 periods/year), (2) clinical hyperandrogenism (hirsutism, acne, alopecia) or biochemical hyperandrogenism (elevated free testosterone or FAI), or (3) polycystic ovarian morphology on ultrasound (≥20 follicles per ovary or ovarian volume >10 mL). Other causes must be excluded.
Is PCOS curable?▾
PCOS is not curable but is very manageable. Symptoms can be effectively controlled with lifestyle changes (diet, exercise, weight management), medications (metformin for insulin resistance, OCP for androgen suppression, letrozole for ovulation induction), and for fertility specifically — IVF when needed. Many women with PCOS live healthy, symptom-free lives with appropriate management.
Does PCOS cause weight gain?▾
PCOS and obesity have a bidirectional relationship. PCOS-associated insulin resistance promotes fat storage, particularly abdominal fat, making weight management harder. However, not all women with PCOS are overweight — lean PCOS (normal BMI with PCOS features) affects approximately 20–30% of PCOS patients, particularly in Asian populations.