How Common Is PCOS? UK Prevalence & Facts

How common is PCOS? Polycystic ovary syndrome affects roughly 1 in 10 people with ovaries in the UK, making it one of the most prevalent hormonal conditions in those of reproductive age. Despite this, it remains widely underdiagnosed, with many people waiting years for a formal diagnosis. This article explores how common PCOS is, who is most at risk, what symptoms to look out for, how it is diagnosed on the NHS, and what treatment and support options are available in the UK.

How common is PCOS in the UK?

PCOS affects roughly 1 in 10 people with ovaries in the UK and is considered widely underdiagnosed, with global prevalence ranging from 6% to 15% depending on the diagnostic criteria applied.

Polycystic ovary syndrome (PCOS) affects roughly 1 in 10 people with ovaries in the UK, making it one of the most common hormonal conditions seen in reproductive-age women and those assigned female at birth.^[1][2] This figure is cited by the NHS PCOS overview and is broadly consistent with estimates from NICE Clinical Knowledge Summaries (CKS). Separately, around 1 in 5 women may show polycystic-appearing ovaries on ultrasound; however, this proportion varies depending on the ultrasound criteria and equipment used, and the majority of these individuals will not meet the full diagnostic criteria for PCOS.^[5] Globally, prevalence estimates range from approximately 6% to 15% of the reproductive-age population, depending on the diagnostic criteria applied, as summarised in the 2023 international evidence-based guideline on PCOS published by the European Society of Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM).^[3][4]

Despite its frequency, PCOS is widely considered to be underdiagnosed, with many people living with symptoms for years before receiving a formal diagnosis. This reflects both the variability of presentation and limited awareness among patients and clinicians, as noted in NICE CKS commentary on the condition. Some individuals experience only mild irregularities, while others face significant hormonal, metabolic and reproductive challenges.

PCOS does not affect only those of reproductive age. While it is most commonly identified during the teens and twenties, the associated metabolic risks, including a higher likelihood of developing type 2 diabetes and cardiovascular disease, remain relevant throughout life. Raising awareness of how widespread PCOS is helps ensure that more people seek timely assessment and appropriate support.

What causes PCOS and who is most at risk?

PCOS has no single cause; insulin resistance, elevated androgens and genetic factors all contribute, with family history, excess abdominal weight and South Asian ethnicity associated with higher risk.

PCOS does not have a single identified cause, but research consistently points to a combination of genetic, hormonal and metabolic factors. Insulin resistance is present in a significant proportion of people with PCOS and is thought to drive elevated levels of androgens (male-type hormones such as testosterone), which in turn disrupt normal ovarian function.^[3][4] This insulin resistance and hyperandrogenism relationship is described in the 2023 ESHRE/ASRM PCOS guideline and in NICE CKS. The pituitary gland may also release higher-than-normal levels of luteinising hormone (LH) in some people with PCOS, contributing to hormonal imbalance; however, elevated LH is neither required for a diagnosis nor specific to PCOS, and the LH:FSH ratio is not a recommended diagnostic test in UK guidance.^[2][10]

Genetics play a meaningful role. Having a first-degree relative, such as a mother or sister, with PCOS or type 2 diabetes increases an individual's likelihood of developing the condition, though no single gene has been identified as solely responsible. This suggests a polygenic pattern of inheritance that interacts with environmental and lifestyle factors.

Certain groups appear to be at higher risk:

• Family history: A close relative with PCOS or type 2 diabetes raises the risk.

• Body weight: Excess weight, particularly around the abdomen, can worsen insulin resistance and amplify hormonal disruption, though PCOS also affects people with a healthy body weight. Central adiposity acts as a risk enhancer rather than a direct cause.

• Ethnicity: Some studies, including UK-relevant data cited in the 2023 ESHRE/ASRM guideline, suggest higher prevalence and more severe metabolic features in South Asian populations, though PCOS affects people of all ethnic backgrounds.

• Age: Symptoms most commonly emerge during puberty or the early reproductive years.

It is important to note that PCOS is not caused by anything a person has done, and lifestyle factors alone do not explain its development.

What are the most common symptoms of PCOS?

The most common symptoms are irregular or absent periods, hirsutism, acne and fertility difficulties, though presentation varies and symptoms can fluctuate over time.

The most common symptoms of PCOS include irregular or absent menstrual periods, excess hair growth (hirsutism), acne and difficulty conceiving, though the condition varies considerably between individuals. Because no two presentations are identical, PCOS can be easy to overlook or attribute to other causes.

The main symptoms can be grouped as follows:

• Menstrual irregularities: Periods may be infrequent (fewer than eight per year), unpredictable or absent altogether. This reflects disrupted ovulation.

• Androgen-related features: Elevated androgens can cause hirsutism (unwanted hair on the face, chest or back), acne on the face or body, and, in some cases, thinning of scalp hair (androgenic alopecia).

• Polycystic ovaries: On ultrasound, the ovaries may appear enlarged and contain multiple small follicles. This finding alone does not confirm PCOS.

• Metabolic skin signs: Some people with insulin resistance develop acanthosis nigricans (darkened, velvety patches of skin, typically at the neck or armpits) or skin tags, which can aid recognition of the metabolic component.

• Weight changes: Many people with PCOS find it harder to manage their weight, and weight gain can worsen symptoms.

• Fertility difficulties: Irregular ovulation is a leading cause of difficulty conceiving, though many people with PCOS do go on to have successful pregnancies with appropriate support.

• Mood and wellbeing: Anxiety, low mood and reduced quality of life are reported more frequently in people with PCOS, though the relationship is complex and not fully understood.^[14][15]

Symptoms can fluctuate over time and may change after pregnancy or around the menopause.

When to seek prompt medical advice: Anyone with amenorrhoea (no period) lasting more than 90 days, very heavy or prolonged bleeding, bleeding between periods, or new virilising features such as voice deepening or clitoromegaly should seek prompt GP review, as these may indicate alternative or additional pathology requiring urgent assessment. Rapid-onset or severe hirsutism also warrants early review to exclude other causes.

Endometrial health: Infrequent or absent periods mean the uterine lining may not shed regularly, which over time can increase the risk of endometrial hyperplasia. NICE CKS advises that a withdrawal bleed should be induced at least every three to four months in people with oligomenorrhoea or amenorrhoea who are not using combined hormonal contraception.^[2][7] Anyone concerned about this should discuss options with their GP.

How is PCOS diagnosed on the NHS?

PCOS is diagnosed using the Rotterdam criteria, requiring at least two of three features: irregular ovulation, elevated androgens and polycystic ovaries on ultrasound, after excluding other conditions.

PCOS is diagnosed on the NHS using the Rotterdam criteria, which require at least two of the following three features to be present: irregular or absent ovulation, clinical or biochemical signs of elevated androgens, and polycystic ovaries visible on ultrasound. A diagnosis cannot be made on ultrasound findings alone, and other conditions that can mimic PCOS must be excluded first.

A GP will typically begin with a detailed history of menstrual patterns, symptoms and family background, followed by a physical examination. Blood tests are central to the investigation and usually include:

• Hormone levels: LH, follicle-stimulating hormone (FSH), testosterone, sex hormone-binding globulin (SHBG) and prolactin.

• Glycaemic status and diabetes risk: Fasting glucose or HbA1c to assess blood sugar levels and screen for impaired glucose regulation or type 2 diabetes. These tests assess glycaemic status rather than insulin resistance directly.

• Lipid profile: A fasting lipid profile to assess cardiovascular risk.

• Thyroid function: To exclude thyroid disorders, which can cause similar symptoms.

• Additional tests where indicated: A pregnancy test is appropriate for amenorrhoea. Early-morning 17-hydroxyprogesterone may be measured to exclude non-classic congenital adrenal hyperplasia where biochemical hyperandrogenism is present.^[2][7] DHEAS or androstenedione may be checked where the source of androgen excess is uncertain.

A pelvic ultrasound may be arranged to assess ovarian morphology, though NICE CKS acknowledges that ultrasound is not always necessary if the other two Rotterdam criteria are already met. In adolescents, ultrasound is generally not recommended within eight years of menarche, as polycystic-appearing ovaries are common in the years immediately following puberty and findings are difficult to interpret reliably; the 2023 ESHRE/ASRM guideline supports this caution.

If initial investigations suggest PCOS, the GP may refer to a gynaecologist or endocrinologist for further assessment. Referral is particularly important where there is diagnostic uncertainty, a concern about fertility, markedly elevated androgens, or rapidly progressive or virilising symptoms, which require prompt specialist review. NICE recommends that all people diagnosed with PCOS are offered information about the long-term health implications, including cardiovascular and metabolic risk, as part of their care.^[7][2]

What treatment and support is available for PCOS in the UK?

NHS treatment is tailored to individual symptoms and goals, with lifestyle modification as the foundation, alongside hormonal contraception, anti-androgens, metformin or ovulation induction depending on needs.

Treatment for PCOS on the NHS is tailored to an individual's symptoms and goals, with lifestyle modification forming the foundation of management for most people. Even a modest reduction in body weight, where relevant, can meaningfully improve hormonal balance, restore more regular ovulation and reduce androgen-related symptoms. NICE CKS supports a structured approach that addresses both the immediate symptoms and the longer-term metabolic risks associated with the condition.

Regulating periods and protecting the endometrium: For those not trying to conceive, the combined oral contraceptive pill is commonly prescribed to regulate periods and reduce androgen-driven symptoms such as acne and hirsutism. For people who cannot use or prefer not to use combined hormonal contraception, cyclic oral progestogen or a levonorgestrel intrauterine system (IUS) are alternatives that also provide endometrial protection. Regardless of the approach chosen, NICE CKS advises that a withdrawal bleed should be induced at least every three to four months in people with oligomenorrhoea or amenorrhoea, to reduce the risk of endometrial hyperplasia.^[2][7]

Managing androgen-related symptoms: Anti-androgen medications may be considered where hirsutism or acne is more pronounced. These medicines must not be taken during pregnancy because of the risk of harm to a male fetus; effective contraception is therefore essential throughout treatment, and prescribing is typically under specialist oversight.^[2][10] Topical treatments and cosmetic approaches (such as laser hair removal) can also help manage hirsutism.

Ovulation induction for those trying to conceive: For people with PCOS who are trying to conceive, ovulation induction is available through NHS fertility services. Letrozole is now widely used as a first-line agent in this context, in line with current NICE fertility guideline recommendations; it is used off-label for this indication in the UK, and its use should be discussed with a specialist.^[8][10] Clomifene citrate may also be offered. Where these are unsuccessful, referral for further assisted reproduction may be appropriate, subject to local Integrated Care Board (ICB) commissioning decisions.

Metabolic health: People with insulin resistance or impaired glucose regulation may benefit from metformin, which can improve insulin sensitivity and support more regular cycles. Metformin is used off-label for PCOS in the UK; its use should be guided by a clinician and is supported by NICE CKS. Regular monitoring of blood glucose, blood pressure and lipids is recommended, with frequency guided by individual risk and local clinical protocols.

Mental health support: Psychological therapies, including cognitive behavioural therapy (CBT), are available through NHS Talking Therapies for those experiencing anxiety or low mood related to their diagnosis. Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online consultations, with prescriber review and pharmacist support, for those exploring their options alongside NHS care. Patient support organisations such as Verity (the UK PCOS charity) also provide peer support and reliable information.

Scientific References

1. Polycystic ovary syndrome (PCOS) – NHS overview.
2. Polycystic ovary syndrome – NICE Clinical Knowledge Summaries.
3. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome (ESHRE/ASRM).
4. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome (full guideline, ESHRE/ASRM).
5. How common are polycystic ovaries in normal women and what is their significance for the fertility of the population? (Clayton RN et al., Clinical Endocrinology, 1992).
6. Polycystic ovary syndrome (PMOS) – NICE guideline supporting documentation (prevalence and ethnicity data).
7. Polycystic ovary syndrome (PMOS) – NICE guideline (GID-NG10436).
8. Polycystic ovary syndrome: adaptation report 5 – NICE (letrozole/ovulation induction).
9. Polycystic ovary syndrome: metformin in women not planning pregnancy (ESUOM6) – NICE.
10. Polycystic ovary syndrome – Treatment summaries, BNF/NICE.
11. Adolescents diagnosed with polycystic ovary syndrome under the Rotterdam criteria but not meeting the diagnosis under the updated guideline. Human Reproduction. 2024..
12. The value of anti-Mullerian hormone for diagnosing polycystic ovary syndrome in adolescents: a case-control study based on an epidemiological survey. Frontiers in Reproductive Health. 2025..
13. Polycystic ovary syndrome: Criteria, phenotypes, race and ethnicity. Reproductive Medicine and Biology. 2025..
14. Integrated cellular and molecular mechanisms of neuropsychiatric dysfunction in polycystic ovary syndrome. Journal of Psychiatric Research. 2025..
15. The lived experiences of women with polycystic ovary syndrome and its psychological challenges: A systematic review and meta-synthesis. Archives of Women's Mental Health. 2025..

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