How to Know If You Have PCOS: Signs & Tests

Knowing how to tell if you have PCOS can feel overwhelming, particularly when symptoms overlap with other conditions. Polycystic ovary syndrome (PCOS) is one of the most common hormonal conditions in the UK, affecting around 1 in 10 women of reproductive age, yet it is frequently diagnosed late or missed altogether. Irregular periods, unwanted hair growth, persistent acne and difficulty managing weight are among the most recognised signs, but the condition presents differently in each person. This article explains what to look for, what else could be causing your symptoms, and what steps to take if you suspect you have PCOS.

What is PCOS and how common is it in the UK?

PCOS affects roughly 1 in 10 women of reproductive age in the UK and is diagnosed when at least two of three Rotterdam criteria are met: irregular ovulation, elevated androgens, or polycystic ovarian morphology on ultrasound.

Polycystic ovary syndrome (PCOS) is one of the most common hormonal conditions affecting people with ovaries in the UK. The NHS estimates it affects roughly 1 in 10 women of reproductive age. Despite its name, PCOS does not necessarily mean you have cysts on your ovaries. The term refers to a cluster of features related to hormonal imbalance, particularly elevated levels of androgens (sometimes called male hormones), disrupted ovulation, and characteristic changes visible on an ultrasound scan.

Diagnosis is based on the Rotterdam criteria, which require at least two of three features to be present: irregular or absent ovulation, clinical or biochemical signs of elevated androgens, and polycystic ovarian morphology on ultrasound. This framework is used by clinicians in the UK and internationally and is referenced in NICE Clinical Knowledge Summaries (CKS) on PCOS.

The exact cause of PCOS is not fully understood, but insulin resistance and genetic factors are thought to play a significant role. Many people with PCOS also have higher-than-average insulin levels, which can stimulate the ovaries to produce excess androgens. This hormonal disruption then interferes with the normal development and release of eggs during the menstrual cycle.

PCOS can affect people across all ethnicities and body types, though some research suggests it may be more prevalent or present differently in certain populations. It is also worth noting that PCOS is a spectrum condition: symptoms vary considerably from person to person, and some individuals may have very mild features while others experience significant impact on their daily life and fertility. Because of this variability, PCOS is frequently underdiagnosed or diagnosed late, sometimes only when a person is trying to conceive.

What are the signs and symptoms that might mean you have PCOS?

The most common signs of PCOS are irregular or infrequent periods, excess facial or body hair, persistent acne, scalp hair thinning and difficulty managing weight, though not all features need to be present for a diagnosis.

You might have PCOS if you experience irregular or infrequent periods, excess hair growth, persistent acne, or unexplained weight gain, particularly around the abdomen. These are among the most commonly reported features, and the NHS and NICE both recognise them as key indicators that warrant further investigation. However, not everyone with PCOS will have all of these symptoms, and the condition can present in quite different ways.

The main signs and symptoms to be aware of include:

• Irregular periods: Cycles that are longer than 35 days, fewer than eight periods per year, or periods that stop altogether (thresholds referenced in NICE CKS on PCOS and NHS guidance)^[2][6]

• Excess androgen effects: Unwanted or excessive hair growth on the face, chest, back or abdomen (hirsutism); acne that does not respond well to standard treatments; or thinning hair on the scalp. These may be clinical signs of hyperandrogenism, or elevated androgens may be detected on a blood test (biochemical hyperandrogenism)

• Polycystic ovarian morphology on ultrasound: Ovaries that appear enlarged or contain 20 or more follicles in at least one ovary, or an ovarian volume of 10 mL or more in at least one ovary, as described in the International PCOS Guideline (2018, updated 2023)^[7][10]

• Weight changes: Difficulty managing weight, particularly gaining weight around the waist. Some people with PCOS also develop acanthosis nigricans (darkened, velvety patches of skin, typically at the neck or armpits), which can be a sign of insulin resistance

• Mood changes: Anxiety, low mood or difficulty concentrating, which some research links to the hormonal fluctuations associated with PCOS

• Fertility difficulties: Irregular ovulation can make it harder to conceive naturally

It is important to note that a diagnosis of PCOS requires at least two of the three Rotterdam criteria to be met. Polycystic ovarian morphology on ultrasound alone does not confirm PCOS, and clinical or biochemical hyperandrogenism must be distinguished from other causes. Experiencing one symptom alone does not confirm the condition, which is why a formal clinical assessment is essential.

In adolescents, ultrasound is generally not recommended for diagnosing PCOS within eight years of the first period (menarche), because polycystic ovarian morphology can be a normal finding in this age group.^[9][10] In younger people, diagnosis should rely primarily on clinical and biochemical features, in line with the International PCOS Guideline.

Could something else be causing your symptoms?

Thyroid disorders, hyperprolactinaemia and congenital adrenal hyperplasia can all produce PCOS-like symptoms, so blood tests to exclude these conditions are a standard part of the diagnostic process.

Several other medical conditions can produce symptoms that closely resemble PCOS, so a thorough clinical assessment is necessary before a diagnosis is confirmed. Thyroid disorders, for example, can cause irregular periods, weight changes and fatigue. Hyperprolactinaemia (elevated prolactin levels) can also disrupt the menstrual cycle and is important to exclude. Congenital adrenal hyperplasia (CAH), a condition affecting the adrenal glands, can cause excess androgen production and may mimic PCOS closely; a blood test for early-morning 17-hydroxyprogesterone is used to screen for the non-classical form.

Other conditions worth considering include:

• Cushing's syndrome: Caused by prolonged exposure to high cortisol levels, this can produce weight gain, acne and menstrual irregularities

• Androgen-secreting tumours: Rare, but an important cause of rapidly progressive hirsutism or virilisation (features such as deepening of the voice, clitoral enlargement or marked masculinisation). These features warrant urgent assessment

• Primary ovarian insufficiency: Can cause infrequent or absent periods but is associated with low rather than high oestrogen levels

• Endometriosis: Shares some overlapping symptoms such as pelvic pain and fertility difficulties, though its hormonal profile differs from PCOS

A pregnancy test is also standard practice when investigating absent or infrequent periods. Where significant hyperandrogenism is suspected, your GP may also check DHEAS (dehydroepiandrosterone sulphate) and androstenedione levels to help identify adrenal causes.

Certain medications, including some antipsychotics and hormonal treatments, can also alter menstrual patterns or androgen levels. Your GP will typically request blood tests to measure hormone levels, including luteinising hormone (LH), follicle-stimulating hormone (FSH), testosterone, thyroid function, and prolactin. For diabetes screening, UK guidance (NICE CKS) recommends HbA1c or fasting plasma glucose rather than fasting insulin, which is not a recommended routine test in primary care.^[2][6] Where results are equivocal or risk is higher, a 75 g oral glucose tolerance test (OGTT) may be considered. This process of exclusion is a standard and important part of reaching an accurate diagnosis, and it is why self-diagnosis based on symptoms alone is not recommended.

What should you do if you think you have PCOS?

Book an appointment with your GP, who can take a history, arrange hormone blood tests and refer you for a pelvic ultrasound; no specialist referral is needed to begin the investigation.

If you think you might have PCOS, the right first step is to make an appointment with your GP to discuss your symptoms and request appropriate investigations. You do not need a referral to a specialist to begin this process. Your GP can take a detailed history, arrange blood tests and, if indicated, refer you for a pelvic ultrasound scan. NICE guidance supports a structured approach to investigation, and most initial assessments can be completed in primary care.

To make the most of your appointment, it can help to:

• Keep a menstrual diary for at least two to three months before your appointment, noting cycle length, flow and any associated symptoms

• Note any other symptoms such as skin changes, hair growth patterns, mood changes or weight fluctuations

• List any medications you are currently taking, including contraceptives, as these can affect hormone levels and menstrual patterns. If you have recently stopped a combined oral contraceptive, your GP may advise waiting before testing, as hormone levels can take time to normalise

• Ask about next steps if initial tests are inconclusive, including whether a referral to a gynaecologist or endocrinologist is appropriate

For those seeking additional support or a weight-management consultation alongside their PCOS assessment, Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online consultations with prescriber review and pharmacist support, which may be relevant if weight management forms part of your care plan.

If you are trying to conceive and suspect PCOS, mention this clearly to your GP, as it may affect the urgency and direction of your referral. NICE fertility guidance suggests that earlier referral may be appropriate for people aged over 35 or where significant anovulation is confirmed.^[8] You should contact your GP promptly if you have not had a period for more than three months, are experiencing heavy or prolonged abnormal uterine bleeding, have significant pelvic pain, or are concerned about sudden or rapidly progressive changes in hair growth, skin or other features that could suggest virilisation.

How does a PCOS diagnosis affect your long-term health?

PCOS raises the long-term risk of type 2 diabetes, cardiovascular disease and endometrial hyperplasia, so regular monitoring of blood glucose, blood pressure and menstrual regularity is recommended.

A PCOS diagnosis has implications beyond reproductive health, and understanding these long-term considerations can help you and your healthcare team make informed decisions about monitoring and management. People with PCOS have a higher risk of developing type 2 diabetes, particularly if insulin resistance is present. NICE CKS recommends regular screening using HbA1c or fasting plasma glucose, with a 75 g oral glucose tolerance test considered where results are borderline or risk factors are present.^[2][13] The International PCOS Guideline (2023 update) suggests reassessment every one to three years depending on individual risk, though your GP will advise on the interval most appropriate for you.

Other long-term health considerations associated with PCOS include:

• Cardiovascular risk: Elevated androgens, insulin resistance and dyslipidaemia can contribute to an increased risk of high blood pressure and cardiovascular disease over time. Baseline and periodic checks of blood pressure and a fasting lipid profile are therefore recommended as part of ongoing monitoring

• Endometrial health: Infrequent periods mean the uterine lining may not shed regularly, which over time can increase the risk of endometrial hyperplasia and, in some cases, endometrial cancer. UK guidance generally considers having at least four periods per year to be protective. Where periods are infrequent, your GP or specialist may recommend a combined oral contraceptive pill or cyclical progestogen (taken every three to four months) to induce regular withdrawal bleeds and protect the endometrium. If you experience heavy or prolonged bleeding, seek prompt review

• Mental health: Anxiety and depression are more common in people with PCOS, and psychological support should be considered as part of holistic care

• Sleep: There is an association between PCOS and obstructive sleep apnoea, particularly in those with obesity^[16][17]

• Pregnancy-related risks: People with PCOS have a higher risk of gestational diabetes and may benefit from additional monitoring during pregnancy^[15][7]

The good news is that many of these risks can be meaningfully reduced through lifestyle measures, including a balanced diet, regular physical activity and maintaining a healthy weight. Where lifestyle measures are insufficient, your GP or specialist may discuss medical options. Hormonal contraception (such as the combined oral contraceptive pill) is commonly used to regulate periods and manage androgen-related symptoms. Metformin is sometimes considered to address insulin resistance and metabolic features; it is important to be aware that its use in PCOS is off-label in the UK, meaning it is not formally licensed for this indication, and it is typically considered when lifestyle measures and hormonal contraception are unsuitable or have not been sufficiently effective.^[3][4] Any decision about medication should be made with your GP or specialist based on your individual circumstances. Regular follow-up with your GP is important to monitor these risks over time and adjust your care plan as your circumstances change.

Scientific References

1. Polycystic ovary syndrome (PCOS).
2. Polycystic ovary syndrome – NICE Clinical Knowledge Summaries.
3. Polycystic ovary syndrome: metformin in women not planning pregnancy (ESUOM6) – Key points from the evidence.
4. Polycystic ovary syndrome: metformin in women not planning pregnancy (ESUOM6) – Overview for healthcare professionals.
5. Polycystic ovary syndrome: metformin in women not planning pregnancy (ESUOM6) – Full PDF.
6. Polycystic ovary syndrome – Treatment summaries, BNF.
7. Recommendations from the 2023 International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome.
8. Fertility problems: assessment and treatment (CG156).
9. Adolescent polycystic ovary syndrome according to the international evidence-based guideline.
10. International evidence-based recommendations for polycystic ovary syndrome in adolescents. BMC Medicine.
11. Steroid screening tools differentiating nonclassical congenital adrenal hyperplasia from polycystic ovary syndrome.
12. Hyperandrogenism in polycystic ovary syndrome and adrenal hyperplasia: finding differences to make a specific diagnosis. Archives of Gynecology and Obstetrics.
13. Diagnosis of disorders of glucose tolerance in women with polycystic ovary syndrome.
14. Diabetes in pregnancy: management from preconception to the postnatal period (NG3).
15. Prevalence and associated factors of gestational diabetes mellitus among women with polycystic ovary syndrome: a systematic review and meta-analysis. Frontiers in Endocrinology.
16. Prevalence of obstructive sleep apnea in patients with polycystic ovary syndrome: a systematic review and meta-analysis. British Journal of Hospital Medicine.
17. Obstructive sleep apnea syndrome in polycystic ovary syndrome: a systematic review and meta-analysis. Frontiers in Endocrinology.
18. PCOS/PMOS guideline (GID-NG10436).

Frequently Asked Questions