How is PMOS (PCOS) diagnosed in the UK? 

Getting diagnosed with PMOS (PCOS), should not take years. Yet many people are dismissed, told their symptoms are normal, or given the pill without being told what is driving their irregular periods, acne, excess hair growth or fertility concerns.

PMOS is diagnosed using the Rotterdam criteria. This means you need to meet at least 2 out of 3 criteria: irregular or absent periods, signs of high androgens, and/or polycystic ovarian morphology on ultrasound or AMH testing. Other conditions, such as thyroid disorders and raised prolactin, should also be ruled out.

This guide explains the tests used to diagnose PMOS, what the criteria mean, whether you need an ultrasound, and what to do if you are not getting clear answers.

Quick facts:

• PMOS (polyendocrine metabolic ovarian syndrome) is diagnosed using the Rotterdam criteria, you need to meet at least 2 out of 3 specific criteria.
• There is no single definitive test for PMOS. Diagnosis requires a combination of symptom history, blood tests, and in some cases an ultrasound scan.
• AMH is now formally accepted as an alternative to ultrasound for assessing polycystic ovarian morphology
• Other conditions, particularly thyroid disorders and elevated prolactin, must be ruled out before a PMOS diagnosis is confirmed.

What tests are used to diagnose PMOS (PCOS)?

There is no single test that can diagnose polyendocrine metabolic ovarian syndrome, or PMOS. Instead, diagnosis is usually based on a combination of your symptoms, menstrual cycle pattern, hormone levels, metabolic health markers and, in some cases, an ultrasound scan.

Your doctor may recommend a combination of the following assessments.

Medical history and symptom assessment

The first step is usually a detailed conversation about your symptoms and health history. This may include questions about:

• How regular your periods are
• Whether you ovulate regularly
• Acne, excess facial or body hair, or hair thinning
• Weight changes or difficulty managing weight
• Symptoms of insulin resistance
• Fertility or difficulty conceiving
• Family history of PMOS, type 2 diabetes or metabolic conditions

This helps build a clearer picture of whether your symptoms fit with PMOS and whether other conditions need to be ruled out.

Physical examination

A clinician may also look for physical signs that can be associated with PMOS. These may include acne, excess facial or body hair, scalp hair thinning, skin tags or darker velvety patches of skin, which can sometimes be linked to insulin resistance. This helps identify patterns that may guide further testing.

Blood tests for PMOS (PCOS)

Blood tests are often used to check hormone levels, assess metabolic health and rule out other conditions that can cause similar symptoms.

These may include:

• Androgen hormones, such as testosterone and DHEA-S, which can be raised in PMOS and contribute to acne, excess hair growth or hair thinning
• AMH, which can be higher in people with a high number of small ovarian follicles
• FSH and LH, which help assess how the brain and ovaries are communicating
• Thyroid function tests, because thyroid conditions can affect periods and ovulation
• Prolactin, because raised prolactin can disrupt ovulation and mimic some PMOS symptoms
• Glucose or HbA1c testing, to assess blood sugar regulation
• Fasting insulin or glucose tolerance testing, where appropriate, to investigate insulin resistance
• Lipid profile, to check cholesterol and wider metabolic health
• Vitamin D, which may be checked depending on your symptoms, risk factors or clinician’s judgement

These tests help identify whether PMOS is likely, how it may be affecting your body, and what kind of support may be most appropriate.

Pelvic ultrasound scan for PMOS (PCOS)

A pelvic ultrasound may be recommended to look at the ovaries and uterus. This can help assess whether the ovaries have a polycystic appearance, meaning they contain a higher number of small follicles.

A transvaginal ultrasound is often used because it provides a clearer view of the ovaries. This involves placing a slim ultrasound probe into the vagina, which uses sound waves to create images on a screen.

However, having polycystic-looking ovaries alone is not enough to diagnose PMOS. Some people have polycystic ovaries without symptoms, and some people with PMOS may not have obvious changes on ultrasound.

Pelvic examination

In some cases, a pelvic examination may be offered to check for abnormalities or signs of other reproductive health conditions. This is not always needed for a PMOS diagnosis, but it may be useful if you have symptoms such as pelvic pain, abnormal bleeding or pain during sex.

Testing does more than confirm a diagnosis. It can help rule out other causes of irregular periods, acne, excess hair growth or difficulty conceiving, and it can identify whether PMOS is affecting ovulation, hormone balance or metabolic health.

That means your care can be tailored to what is actually happening in your body, whether that involves cycle support, fertility planning, skin and hair treatment, metabolic health support or longer-term monitoring.

How is PMOS/PCOS diagnosed?

PMOS is diagnosed using the Rotterdam criteria, the internationally recognised diagnostic framework, most recently updated in the 2023 International Evidence-Based PCOS Guidelines. To receive a diagnosis, you must meet at least 2 of the following 3 criteria. You do not need all three.

Criterion 1: Irregular or absent menstrual cycles

This criterion reflects the disruption to ovulation that is central to PMOS. When elevated androgens interfere with follicle development, ovulation doesn’t happen reliably, and without ovulation, the regular hormonal cycle that produces a period is disrupted.

What counts as irregular? 

• Fewer than 8 menstrual cycles per year

• Cycles consistently shorter than 21 days or longer than 35 days, in women who are at least 3 years post-menarche (3 or more years after their first period)
• Complete absence of periods (amenorrhoea)

A single late or missing period doesn’t meet this criterion, it needs to be a consistent pattern, not an occasional variation.

Criterion 2: Clinical or biochemical hyperandrogenism (elevated androgens)

This criterion reflects the androgen excess that is the hormonal driver of many PMOS symptoms. It can be met in two ways, through physical symptoms, or through blood test results, either is sufficient.

Clinical hyperandrogenism means physical signs of elevated androgen activity:

• Hirsutism – excess coarse hair growth on the upper lip, chin, jaw, chest, stomach, lower back, or inner thighs. This is the most reliable clinical marker of androgen excess.
• Hormonal acne – particularly along the jawline, chin and lower face. 
• Androgenic alopecia – scalp hair thinning at the temples or crown, following a male-pattern distribution. 

Biochemical hyperandrogenism means elevated androgens on a blood test including high testosterone and DHEAS. SHBG is a protein that binds to testosterone and reduces its biological activity. In PMOS, SHBG is often low, meaning more testosterone is free and active. This is why a PMOS-focused blood panel should always include SHBG alongside testosterone, not testosterone in isolation.

Hormonal contraception can raise SHBG significantly, which suppresses testosterone and can mask androgen excess entirely. If you’re on or have recently stopped the pill, your androgen levels may not reflect your true baseline for several months. Ideally, androgens should be tested at least 3 full cycles after stopping hormonal contraception for the most accurate picture.

Criterion 3: Polycystic ovarian morphology (PCOM)

This criterion refers to evidence of the characteristic ovarian appearance associated with PMOS, a high number of follicles that haven’t been able to progress to ovulation. It can now be assessed in two ways:

Transvaginal ultrasound (TVUS) A pelvic ultrasound scan counts the number of follicles visible in each ovary. The scan should ideally be performed in the early follicular phase, days 1-7 of the menstrual cycle, when follicles are at their most clearly countable. 

AMH blood test This is the significant change introduced in the updated 2023 guidelines. AMH (anti-Müllerian hormone) is a hormone made by the follicles themselves. In PMOS, AMH is typically elevated, reflecting the high number of small arrested follicles.

AMH is now formally accepted as an alternative to ultrasound for assessing polycystic ovarian morphology. This means that for many people, a blood test alone can support this third criterion, without the need for an internal transvaginal scan.

Can AMH diagnose PMOS (PCOS)?

AMH can help support a PMOS/PCOS diagnosis, but it should not be used on its own.

AMH, or anti-Müllerian hormone, is made by the small follicles in the ovaries. People with PMOS/PCOS, often have a higher number of small follicles, which means AMH levels can be raised.

Under the updated 2023 International Evidence-Based PCOS Guidelines, AMH can now be used as an alternative to ultrasound when assessing polycystic ovarian morphology, which is one of the three Rotterdam diagnostic criteria.

This means AMH can help fulfil the third diagnostic criterion, alongside:

1. Irregular or absent menstrual cycles
2. Clinical or biochemical signs of high androgens
3. Polycystic ovarian morphology, assessed by ultrasound or AMH

However, AMH alone cannot diagnose PMOS. You still need to meet at least 2 out of 3 diagnostic criteria, and other conditions that can cause similar symptoms, such as thyroid disorders or raised prolactin, should be ruled out first.

AMH also needs to be interpreted carefully. Levels can vary depending on age, hormonal contraception, testing method and the laboratory reference range used. A high AMH may suggest a higher number of small ovarian follicles, but it does not automatically mean you have PMOS/PCOS. Equally, a normal AMH does not always rule it out if you meet the other criteria.

What else needs to be ruled out before a PMOS diagnosis?

Before PMOS is confirmed, clinicians usually check whether another condition could be causing similar symptoms, such as irregular periods, acne, excess facial or body hair, hair thinning, weight changes or difficulty ovulating. This is known as a differential diagnosis, and it is an important part of making sure you receive the right diagnosis and care.

Some of the main conditions clinicians may consider include:

Thyroid dysfunction
Both an underactive thyroid and an overactive thyroid can affect your menstrual cycle, energy levels, weight, mood and ovulation. Thyroid function tests, usually including TSH and sometimes free T4, are commonly used to check whether thyroid imbalance could be contributing to symptoms.

Hyperprolactinaemia, or raised prolactin
Prolactin is a hormone made by the pituitary gland. When levels are raised, it can suppress ovulation and lead to irregular or absent periods. Prolactin can be temporarily affected by breastfeeding, stress, illness, certain medications and even sexual activity, breast stimulation, but persistently high levels may need further investigation.

Non-classic congenital adrenal hyperplasia, or CAH
This is a rare inherited condition that can cause higher androgen levels, irregular cycles, acne or excess hair growth, which can overlap with PMOS symptoms. A blood test called 17-hydroxyprogesterone may be used to help rule this out.

Hypothalamic amenorrhoea
This happens when the brain suppresses the hormonal signals needed for ovulation. It can be linked to under-eating, significant weight loss, intense exercise, psychological stress or not fuelling the body adequately. It can cause irregular or absent periods and may sometimes be mistaken for PMOS.

Cushing’s syndrome
Cushing’s syndrome is caused by excess cortisol. It is uncommon, but it can cause symptoms such as irregular periods, acne, weight gain, easy bruising, muscle weakness and changes in fat distribution. Testing is usually only recommended if there are specific clinical signs suggesting it.

Androgen-secreting tumours
These are rare, but clinicians may consider them if androgen symptoms are severe, sudden or rapidly worsening, for example, rapid-onset excess hair growth, deepening of the voice or very high testosterone levels.

Ruling out these conditions matters because the right diagnosis shapes the right treatment. PMOS may share symptoms with other hormone conditions, but the causes and management can be very different. Testing helps make sure your care plan is based on what is actually happening in your body.

What does the PMOS (PCOS) diagnostic process look like step by step with Hertility?

Getting from “I think something’s wrong” to a clear diagnosis and a plan shouldn’t take two years. At Hertility, we’ve built a pathway that compresses that journey:

Step 1: At-home hormone testing. Our Advanced Hormone & Fertility Test checks key PMOS markers such as testosterone, SHBG, DHEAS, LH, FSH, AMH, oestradiol, prolactin, TSH, and Free T3 (FT3). 

Step 2: Clinical interpretation. Your results are reviewed by our clinical team, who interpret them in the context of your symptoms, cycle history and health background, not just against a reference range. You receive a personalised report explaining what your results mean and what they suggest about your hormonal picture.

Step 3: Ultrasound if needed. If your blood results suggest PMOS but an ultrasound would provide additional clarity, our Private Pelvic Ultrasound includes antral follicle count, ovarian volume, and a full assessment of your uterus and ovaries.

Step 4: Specialist consultation and management plan. If your results indicate PMOS, you can book directly with one of  Private Gynaecologists or Private GPs for a consultation and a management plan tailored to your symptoms and goals, whether that’s managing acne, regulating your cycle, supporting fertility, or addressing metabolic health.  Our Nutritionists also offer PMOS-specific consultations focused on insulin resistance, cycle regularity and symptom management through diet and lifestyle.

Frequently asked questions

How is PMOS (PCOS) diagnosed?

PMOS, previously known as PCOS, is diagnosed using the Rotterdam criteria. You need to meet at least 2 out of 3 criteria: irregular or absent periods, clinical or biochemical signs of high androgens, and/or polycystic ovarian morphology, which can be assessed by ultrasound or AMH blood testing. Other causes of similar symptoms, such as thyroid disorders and raised prolactin, should be ruled out before diagnosis.

Can PMOS (PCOS) be diagnosed without an ultrasound?

If you meet criteria 1 (irregular cycles) and criteria 2 (elevated androgens on blood test or physical symptoms), you have sufficient grounds for a PMOS diagnosis without any imaging. For the third criterion, AMH is now formally accepted as an alternative to ultrasound. Many people are diagnosed entirely through symptom history and blood tests, however, it is currently standard practice to get an ultrasound scan to confirm your diagnosis..

Can I have PMOS (PCOS) if my ultrasound is normal?

Yes. An ultrasound that doesn’t show polycystic ovarian morphology does not rule out PMOS if you meet the other two criteria. 60% of people with PMOS are diagnosed on irregular cycles and elevated androgens alone, without any imaging. Similarly, AMH is now an accepted alternative to ultrasound for criterion 3.

Can I test for PMOS (PMOS) at home?

Hertility’s Advanced Hormone & Fertility Test covers all the key PMOS markers from an at-home blood test, with results reviewed by our clinical team who can identify whether your hormonal picture is consistent with PMOS and advise on next steps.

What if my GP says my blood tests are normal but I still have symptoms?

If your cycle history and symptoms are consistent with PMOS but your GP says your tests are normal, it’s worth asking specifically which markers were tested, or pursuing a more comprehensive private panel.

How long does a PMOS diagnosis take?

On average, it takes two years and multiple doctor visits to get a PMOS diagnosis in the UK, largely because investigations are incomplete, symptoms are normalised, or the condition is masked by hormonal contraception. Hertility’s pathway from testing to clinical interpretation takes days, not months.

Can you have PMOS and have regular periods?

Yes. If you have clinical or biochemical evidence of elevated androgens and polycystic ovarian morphology (via AMH or ultrasound), you can meet the criteria for PMOS even with relatively regular cycles. This is one of the less-recognised presentations of the condition.

References

1. Teede HJ et al. (2023). International Evidence-Based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Monash University. https://www.monash.edu/medicine/sphpm/mchri/pcos/guideline
2. Teede HJ et al. (2026). Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(26)00717-8/fulltext
3. NICE (2023). Polycystic ovary syndrome: identification and management (NG239).https://www.nice.org.uk/guidance/ng239
4. Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group (2004). Revised 2003 consensus on diagnostic criteria. Human Reproduction, 19(1), 41–47. https://pubmed.ncbi.nlm.nih.gov/14688154/
5. Azziz R et al. (2009). The androgen excess and PCOS society criteria for the polycystic ovary syndrome. Fertility and Sterility, 91(2), 456–488. https://pubmed.ncbi.nlm.nih.gov/18950759/
6. Dewailly D et al. (2014). Definition and significance of polycystic ovarian morphology: a task force report from the Androgen Excess and Polycystic Ovary Syndrome Society. Human Reproduction Update, 20(3), 334–352. https://pubmed.ncbi.nlm.nih.gov/24345633/
7. Homburg R (2004). Polycystic ovary syndrome. Best Practice & Research Clinical Obstetrics & Gynaecology, 22(2), 261–274. https://pubmed.ncbi.nlm.nih.gov/16275156/
8. Moolhuijsen LME & Visser JA (2020). Anti-Müllerian hormone and ovarian reserve. Journal of Clinical Endocrinology & Metabolism, 105(11), 3361–3373. https://pubmed.ncbi.nlm.nih.gov/32770239/
9. Ding T et al. (2016). Diagnosis and management of PCOS in the UK (2004–2014). BMJ Open. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4947736/
10. Dokras A et al. (2011). Depression and anxiety in women with PCOS. Journal of Clinical Endocrinology & Metabolism, 96(1), 1–12. https://pubmed.ncbi.nlm.nih.gov/20962021/