Polycystic Ovary Syndrome (PCOS)

Ovulatory dysfunction

• Infrequent or absent ovulation – usually manifest as infrequent or no menstruation.

Clinical or biochemical hyperandrogenism

• Hirsutism, acne, or raised total/free testosterone.

• Hirsutism alone predicts biochemical hyperandrogenism and PCOS; acne or female-pattern hair loss in isolation are weaker predictors.

Polycystic ovarian morphology (PCOM)

• ≥ 20 follicles in at least one ovary on ultrasound.

• Polycystic ovaries are neither necessary nor sufficient for the diagnosis on their own.

• Establish the menstrual pattern – cycle length, regularity, bleeds per year, or whether periods have stopped (amenorrhoea)?

• Family history of PCOS, type 2 diabetes, or premature cardiovascular disease?

• Ask about hirsutism – excess terminal hair in a male pattern (face, chest, abdomen)?

• Cardiometabolic risk – weight change, gestational diabetes, hypertension; Black, Asian or mixed ethnicity?

• Identify persistent acne or oily skin, and any female-pattern scalp hair loss?

• Symptoms of obstructive sleep apnoea – snoring, daytime somnolence (common and under-recognised)?

• Explore subfertility – difficulty conceiving, and current or future pregnancy plans?

• Drug history – agents causing hirsutism (e.g. anabolic steroids, ciclosporin)?

• Ask about weight gain or difficulty losing weight?

• Features suggesting an alternative cause – rapid-onset virilisation, galactorrhoea, thyroid symptoms?

• Screen for the psychological impact – low mood, anxiety, disordered eating, and effect on self-esteem and body image?

• Lifestyle – diet, physical activity, and smoking?

➤ "Explore the patient's understanding of the link between hormones, weight and periods, and what a diagnosis would mean to her?"

➤ "Ask how symptoms such as acne, excess hair or subfertility affect her confidence, mood and relationships?"

➤ Rapid-onset or severe hirsutism, or frank virilisation (deepening voice, clitoromegaly, increased muscle bulk) → suspected androgen-secreting tumour → urgent endocrinology / gynaecology referral

➤ Total testosterone > 5 nmol/L or > 2× the upper limit of the local reference range → exclude androgen-secreting tumour and congenital adrenal hyperplasia (CAH) → specialist referral

➤ Features of Cushing's syndrome (purple striae, central obesity, proximal myopathy, easy bruising, thin skin) → investigate and refer

➤ Prolonged amenorrhoea with abnormal or persistent unscheduled bleeding → possible endometrial hyperplasia or carcinoma → urgent endometrial assessment

• BMI and waist circumference – note central adiposity (the metabolic risk cluster and acanthosis nigricans gather here).

• Blood pressure – baseline cardiovascular risk assessment.

• Hirsutism – pattern and severity (e.g. modified Ferriman-Gallwey score); distinguish from generalised hypertrichosis.

• Acne and female-pattern hair loss (androgenic alopecia).

• Acanthosis nigricans – velvety hyperpigmentation in the axillae, neck or groin, signalling insulin resistance.

• Signs prompting exclusion of mimics – virilisation, an abdominal or pelvic mass, Cushingoid features, or goitre.

⚠️ Common pitfall

Diagnosing PCOS in an adolescent on the basis of a scan. Multi-follicular ovaries are a normal finding in the years after menarche, so ultrasound (and AMH) cannot separate PCOS from normal puberty and are not recommended within roughly 8 years of menarche. In this group, diagnosis requires both hyperandrogenism and ovulatory dysfunction; where features are incomplete, treat the symptoms, consider the patient "at risk", and re-evaluate later rather than applying a premature lifelong label.

PCOS is a common hormone imbalance that affects how the ovaries work, often causing irregular periods, acne or extra hair growth.
It can't be cured, but it can be well managed – and looking after your weight, diet and activity has the single biggest effect on your symptoms and long-term health.
Most women with PCOS go on to have children, with a little help if needed.

Total testosterone (with SHBG for free androgen index)

• Confirms biochemical hyperandrogenism; a level > 5 nmol/L prompts exclusion of a tumour or CAH.

• SHBG (sex hormone-binding globulin) is typically low in PCOS.

LH, FSH, prolactin, TSH (± 17-OH-progesterone)

• To exclude mimics – thyroid disease, hyperprolactinaemia, CAH, premature ovarian insufficiency.

• The LH:FSH ratio is no longer diagnostic. (LH, luteinising hormone; FSH, follicle-stimulating hormone.)

Pelvic ultrasound (transvaginal where appropriate)

• Assesses for PCOM in adults when needed.

• Not required if irregular cycles plus hyperandrogenism already confirm the diagnosis, and not used in adolescents.

Anti-Müllerian hormone (AMH)

• An accepted alternative to ultrasound for defining PCOM in adults (2023); not used in adolescents.

HbA1c or oral glucose tolerance test (OGTT)

• Screen for impaired glucose tolerance / type 2 diabetes in all women with PCOS, especially BMI > 25; repeat periodically.

Lipid profile and cardiovascular risk (e.g. QRISK3)

• Assess and manage the elevated cardiometabolic risk that accompanies PCOS.

🧠 Clinical pearl

PCOS is a diagnosis of exclusion, but you often don't need a scan to make it. The 2023 guideline confirms that irregular cycles plus clinical or biochemical hyperandrogenism is sufficient in adults – ultrasound adds nothing and risks over-diagnosis. Where imaging is wanted, AMH is now an accepted alternative. Always exclude thyroid disease, hyperprolactinaemia and CAH before settling on the label.

• Make a positive diagnosis (Rotterdam), exclude mimics, and explain the condition and its lifelong cardiometabolic implications.

• Rapid virilisation or very high testosterone → urgent endocrinology (?androgen-secreting tumour or Cushing's).

• Lifestyle is first-line for everyone – even a 5–10% weight loss can restore ovulation and improve metabolic and androgenic features.

• Prolonged amenorrhoea with abnormal bleeding → urgent endometrial assessment.

• Manage symptoms – combined hormonal contraceptive for cycle control and hyperandrogenism; topical and anti-androgen options for skin and hair.

• Anovulatory subfertility meeting local criteria → refer to fertility services for ovulation induction.

• Protect the endometrium – induce a withdrawal bleed at least every 3–4 months if oligo- or amenorrhoeic.

• Significant psychological distress or eating-disorder features → mental-health support.

• Screen and treat cardiometabolic and mental-health risk lifelong – periodic HbA1c, annual blood pressure and weight, lipids; depression and anxiety are common at all ages, and an eating disorder must not be dismissed on the basis of weight.

• Address fertility proactively – preconception advice on weight, diet, activity, sleep and mental health, folic acid, and timely referral; IVF for those meeting NICE access criteria.

• Offer a structured annual review – recommended in NICE's draft guideline – of symptoms, current medication, and the long-term risks of type 2 diabetes, cardiovascular disease and mental-health problems, while lifestyle change can still help.

🔑 Key principle – treat the lifelong condition, not just today's symptom

PCOS carries a raised lifetime risk of type 2 diabetes, cardiovascular risk factors, obstructive sleep apnoea, fatty liver disease, mood disorders and endometrial cancer. The medical priority is therefore lifestyle, cardiometabolic surveillance, mental-health support and endometrial protection, running alongside whichever symptom-directed treatment the woman chooses. Reassuringly, PCOS does not increase breast or ovarian cancer risk.

Weight management

• Even a 5–10% weight loss improves cycle regularity, ovulation, androgenic symptoms and metabolic risk.

• Offer structured support or dietitian referral.

Diet

• Any nutritionally balanced, calorie-appropriate pattern – no specific "PCOS diet" is superior.

• Frame advice sensitively to avoid compounding low self-esteem.

Physical activity

• At least 150 minutes/week of moderate activity (or 75 minutes vigorous) plus resistance work.

• Benefits insulin sensitivity independently of weight loss.

Cosmetic hair management

• Shaving, waxing, plucking, bleaching or electrolysis.

• NICE's draft guideline does not recommend laser or light-based (IPL) hair reduction on cost-effectiveness grounds, so these are not routinely NHS-funded.

Psychological support

• Screen for and manage anxiety, depression and disordered eating – common at all ages and over-represented.

• Do not dismiss an eating disorder on the basis of weight. Signpost peer support (e.g. Verity, the UK PCOS charity).

Smoking and sleep

• Support smoking cessation.

• Assess and treat obstructive sleep apnoea where suspected.

➤ Menstrual irregularity & hyperandrogenism (first-line)

→ Combined hormonal contraceptive (CHC) – first-line; regulates cycles, protects the endometrium and improves acne and hirsutism. Prefer a lower-dose ethinylestradiol preparation, and check UKMEC eligibility and venous thromboembolism (VTE) risk before prescribing.

→ Cyclical progestogen (e.g. medroxyprogesterone 10 mg for 10–14 days every 1–3 months) – an alternative for endometrial protection where a CHC is unsuitable, though it does not treat androgenic symptoms.

➤ Refractory acne / hirsutism (second-line)

→ Co-cyprindiol (Dianette) – licensed second-line for severe acne or moderately severe hirsutism after topical or antibiotic therapy has failed. It carries a 1.5–2× higher VTE risk than levonorgestrel pills, must not be combined with another hormonal contraceptive (doubling oestrogen exposure), and should be stopped 3–4 months after symptoms are controlled (MHRA).

→ Topical agents – for acne, a topical retinoid ± benzoyl peroxide; for facial hirsutism, eflornithine (Vaniqa) cream in women aged ≥ 18 (not in pregnancy or breastfeeding). Review at 4 months and stop if ineffective, as hair regrows within ~8 weeks of cessation.

→ Anti-androgens (e.g. spironolactone, finasteride) – specialist-led, off-label, with a role where other measures fail. They are teratogenic, so reliable contraception is essential.

➤ Insulin resistance / metabolic features

→ Metformin – off-label; consider for metabolic features or impaired glucose tolerance, and as an adjunct for cycle control, particularly with BMI > 25. Titrate to limit gastrointestinal effects; the modified-release form may aid tolerance.

→ Inositol and other supplements – evidence is limited and inconsistent; not a substitute for lifestyle or established therapy.

➤ Anovulatory subfertility (specialist-initiated)

→ Letrozole – now first-line for ovulation induction (off-label, specialist-supervised), preferred over clomifene for higher live-birth rates.

→ Clomifene (± metformin) – an alternative ovulation-induction agent; gonadotrophins or laparoscopic ovarian drilling are second-line specialist options.

📌 Safety – endometrial protection and cancer risk

• Prolonged unopposed oestrogen from chronic anovulation raises the risk of endometrial hyperplasia and carcinoma. Induce a withdrawal bleed at least every 3–4 months with a CHC or cyclical progestogen, or use the levonorgestrel intrauterine system for continuous protection.

• Investigate persistent intermenstrual or breakthrough bleeding, or amenorrhoea with abnormal bleeding, with transvaginal ultrasound ± endometrial biopsy – do not dismiss it as "just PCOS".

• Rapid virilisation or testosterone > 5 nmol/L → urgent endocrinology (?androgen-secreting tumour)

• Diagnostic uncertainty or complex metabolic features → endocrinology

• Suspected Cushing's syndrome → urgent endocrinology

• Subfertility / conception planning → fertility services for ovulation induction; IVF for those meeting NICE access criteria

• Amenorrhoea with abnormal bleeding → urgent endometrial assessment

• Refractory hirsutism or acne → dermatology / specialist for anti-androgen therapy

• Significant mood disorder or disordered eating → mental-health services

🧭 AKT – high-yield facts

• Rotterdam: any 2 of 3 in adults (hyperandrogenism · ovulatory dysfunction · PCOM on ultrasound or, since 2023, AMH); exclude thyroid disease, hyperprolactinaemia, CAH and Cushing's.

• Adolescents: both hyperandrogenism and ovulatory dysfunction are needed – ultrasound and AMH are not used within ~8 years of menarche.

• Red flag: testosterone > 5 nmol/L (or > 2× upper limit) or rapid virilisation – androgen-secreting tumour until proven otherwise.

• Endometrial protection: induce a bleed at least every 3–4 months (CHC or cyclical progestogen) – unopposed oestrogen risks hyperplasia / carcinoma.

• First-line therapy: lifestyle for all (5–10% weight loss restores ovulation); CHC for cycles and hyperandrogenism; metformin for metabolic features; letrozole first-line for ovulation induction.

• Co-cyprindiol (Dianette): second-line, 1.5–2× VTE risk versus levonorgestrel pills, never alongside another hormonal contraceptive, stop 3–4 months after control.

• Associations: increased type 2 diabetes, cardiovascular risk factors, obstructive sleep apnoea, fatty liver and anxiety/depression; no increase in breast or ovarian cancer.

• Terminology & UK guidance: renamed polyendocrine metabolic ovarian syndrome (PMOS) by international consensus (2026); PCOS remains in current UK use. NICE's first UK guideline is in draft (final December 2026) and recommends a structured annual review.

🎯 SCA

A 15-year-old attends with her mother, two years after menarche, with irregular periods and mild facial acne. Her mother has read about PCOS online and asks you to arrange an ultrasound to "confirm it", worried about her daughter's future fertility. The dilemma is that PCOS cannot be diagnosed on a scan in this age group – multi-follicular ovaries are a normal part of puberty – and applying a premature, lifelong label risks more harm than good, yet the family's anxiety and the genuine symptoms must not be dismissed.

A strong consultation explores the mother's and daughter's ideas, concerns and expectations (ICE), particularly the fear about fertility; explains sensitively and in clear chunks why imaging is not used in adolescents and that a confident diagnosis needs both hormonal and cycle features over time; agrees a shared plan – treat the acne now, encourage a healthy lifestyle, and arrange review rather than rushing to label; and safety-nets for new red flags (rapidly worsening hair growth, virilisation), while respecting the young person's autonomy and confidentiality.