PCOS (Polycystic Ovary Syndrome): Symptoms, Diagnosis & NHS Treatment

Polycystic ovary syndrome (PCOS) is a common hormonal condition affecting around 1 in 10 women of reproductive age in the UK. It causes a range of symptoms including irregular periods, excess androgen (male hormone) effects, and small follicles on the ovaries. Although there is no cure, symptoms can be effectively managed, and many women with PCOS go on to have healthy pregnancies.

What Causes PCOS?

The exact cause of PCOS is not fully understood, but it involves:

• Insulin resistance — elevated insulin levels stimulate the ovaries to produce excess androgens (testosterone and related hormones). Insulin resistance is present in 70-80% of women with PCOS, including many who are not overweight
• Elevated LH (luteinising hormone) — abnormal LH pulsatility stimulates excess androgen production from ovarian theca cells
• Genetic factors — PCOS runs strongly in families; multiple genetic variants contribute
• Obesity — worsens insulin resistance and hyperandrogenaemia, exacerbating symptoms; however, PCOS also occurs in lean women

The elevated androgens and impaired follicular development result in irregular or absent ovulation, multiple small follicles on the ovaries (the “polycystic” appearance), and the characteristic symptoms.

Symptoms of PCOS

PCOS presents with a spectrum of symptoms that vary considerably between individuals:

• Irregular or absent periods (oligomenorrhoea or amenorrhoea) — due to infrequent or absent ovulation; periods may come every 5-6 weeks, or less often, or not at all
• Hirsutism — excess facial or body hair (upper lip, chin, chest, abdomen, thighs) due to elevated androgens
• Acne — often severe or persistent; androgen-driven sebum production
• Alopecia — male-pattern scalp hair thinning
• Weight gain and difficulty losing weight — insulin resistance impairs fat metabolism
• Subfertility — irregular or absent ovulation makes natural conception unpredictable
• Acanthosis nigricans — dark, velvety skin discolouration in skin folds (neck, armpits, groin); indicates significant insulin resistance
• Mood symptoms — anxiety and depression are significantly more common in women with PCOS

Diagnosing PCOS

PCOS is diagnosed using the Rotterdam criteria (2003): two of the following three features are required, with other causes excluded:

• Oligo- or anovulation — irregular or absent periods / infrequent ovulation
• Clinical or biochemical hyperandrogenaemia — hirsutism, acne, or elevated total testosterone/free androgen index on blood test
• Polycystic ovaries on ultrasound — 12 or more follicles (2-9mm) in at least one ovary, or ovarian volume greater than 10ml (in women over 8 years post-menarche)

Investigations

• LH and FSH — LH:FSH ratio may be elevated (greater than 2:1) but is not always present and not a diagnostic criterion
• Total testosterone and SHBG (free androgen index) — confirms biochemical hyperandrogenaemia; also excludes other causes
• Prolactin — elevated prolactin (hyperprolactinaemia) can cause irregular periods and must be excluded
• Thyroid function (TSH) — thyroid disease can mimic or co-exist with PCOS
• Fasting glucose or HbA1c — screens for impaired fasting glucose or type 2 diabetes (recommended at diagnosis and every 1-3 years)
• Fasting lipids — dyslipidaemia is common in PCOS
• Pelvic ultrasound — transvaginal ultrasound for ovarian morphology; transabdominal if the patient is a virgin
• Exclude late-onset congenital adrenal hyperplasia (17-OHP), Cushing’s syndrome, and androgen-secreting tumours if clinical features suggest these diagnoses

NHS Treatment

Treatment is tailored to the patient’s presenting concerns and reproductive goals.

Lifestyle and Weight Management

Lifestyle modification is the cornerstone of PCOS management. Even a 5-10% reduction in body weight in overweight women with PCOS can significantly improve menstrual regularity, ovulation, androgen levels, insulin resistance, and fertility. NICE recommends:

• Regular aerobic and resistance exercise — at least 150 minutes of moderate exercise per week
• A balanced, low-glycaemic-index (low-GI) diet to improve insulin sensitivity
• Avoid excessive calorie restriction — sustainable dietary changes are more effective long-term
• Referral to dietitian for personalised dietary support in those with significant insulin resistance or obesity

Managing Irregular Periods and Endometrial Protection

Women with infrequent periods (fewer than 4 per year) are at increased risk of endometrial hyperplasia and endometrial cancer due to unopposed oestrogen. NICE recommends inducing a withdrawal bleed at least every 3-4 months. Options include:

• Combined oral contraceptive pill (COCP) — the most common first-line treatment for menstrual regulation in PCOS; also treats hirsutism and acne via androgen suppression; pills containing anti-androgenic progestogens (e.g., drospirenone, cyproterone acetate) are most effective for skin and hair symptoms
• Oral progesterone (e.g., norethisterone 10mg daily for 10-14 days) — induces a withdrawal bleed; can be used cyclically if the COCP is not appropriate
• Levonorgestrel IUS (Mirena) — provides endometrial protection and reduces bleeding in women not wishing to use oestrogen

Managing Hirsutism and Acne

• COCP — as above; anti-androgenic pill formulations most effective
• Eflornithine cream (Vaniqa) — prescription topical treatment that slows facial hair growth; licensed for facial hirsutism in women; requires 4-8 weeks to see benefit
• Spironolactone — an anti-androgen that reduces hirsutism and acne; off-licence use in the UK; must be avoided in women who may become pregnant (teratogenic)
• Cosmetic hair removal (laser, IPL, electrolysis) — effective for hirsutism; may be partially funded via NHS in some areas for severe cases
• Dermatology referral for refractory acne — consider isotretinoin for severe acne after standard treatments fail

Fertility Treatment

PCOS is the most common cause of anovulatory infertility. Management is stepwise:

• Step 1 — Lifestyle: Weight loss of 5-10% in overweight women often restores spontaneous ovulation. All women should optimise BMI, stop smoking, and take folic acid before conception
• Step 2 — Ovulation induction with letrozole: NICE recommends letrozole (an aromatase inhibitor) as first-line pharmacological ovulation induction in PCOS. Letrozole is more effective than clomifene citrate and has a lower risk of multiple pregnancy. Typically prescribed in secondary care with ultrasound monitoring
• Step 3 — Clomifene citrate: An alternative oral ovulation induction agent; historically first-line but now second-line per current guidance
• Step 4 — Gonadotrophin injections: FSH injections stimulate follicular development; requires careful ultrasound monitoring due to risk of ovarian hyperstimulation syndrome (OHSS)
• Step 5 — Laparoscopic ovarian drilling (LOD): Surgical procedure using diathermy or laser to destroy androgen-producing ovarian tissue; can restore ovulation in clomifene-resistant PCOS; advantage of single ovulation (low multiple pregnancy risk)
• Step 6 — IVF: For those not responding to other treatments; effective but carries risk of OHSS (a particular concern in PCOS); antagonist protocols and lower stimulation doses reduce OHSS risk

Metabolic Management

Metformin is an insulin-sensitising agent that reduces hyperinsulinaemia and can improve menstrual regularity, ovulation rates, and androgen levels in women with PCOS. NICE supports its use in women with PCOS who have impaired glucose tolerance or metabolic syndrome. It is also used alongside letrozole to improve ovulation induction outcomes. Metformin is not licensed for PCOS but is widely used off-label. Annual HbA1c and cardiovascular risk monitoring are recommended for all women with PCOS.

Long-Term Health Risks in PCOS

Women with PCOS have increased long-term health risks that require monitoring:

• Type 2 diabetes — risk is 4-8 times higher than in women without PCOS; screen every 1-3 years with HbA1c or fasting glucose
• Cardiovascular disease — higher rates of hypertension, dyslipidaemia, and metabolic syndrome; regular blood pressure and lipid checks are recommended
• Endometrial cancer — infrequent periods lead to unopposed oestrogen exposure; ensure regular endometrial shedding (at least every 3-4 months) through hormonal treatment
• Obstructive sleep apnoea — more common in women with PCOS, particularly with obesity; consider investigation if symptoms suggest this
• Mental health — higher rates of depression, anxiety, and eating disorders; regular screening and appropriate support