How PCOS is diagnosed

An ultrasound report mentioning polycystic ovaries is only part of the picture. PCOS cannot be diagnosed from a scan alone, and some people with PCOS do not need a scan at all. The assessment brings symptoms, medical history and selected tests together.

PCOS is now called polyendocrine metabolic ovarian syndrome, or PMOS. Both names refer to the same condition; this article uses PCOS to match the name you may already know.

What clinicians look for in adults

After excluding other explanations, the international guideline uses two of the following features: signs of higher androgen activity, problems with ovulation, and a particular ovarian appearance on ultrasound. In adults, a blood test for anti-Müllerian hormone, called AMH, can be used instead of ultrasound for that ovarian feature.

Androgen activity may be assessed through symptoms and examination or blood tests. Ovulation is the release of an egg; its disruption can show up as irregular or absent periods. A clinician needs to interpret these features alongside your history and test results.

If the assessment has already confirmed irregular cycles and higher androgen activity, ultrasound or AMH is not required for diagnosis. If the ovarian feature needs assessment, the guideline recommends either AMH or ultrasound, rather than routinely doing both. AMH alone is not a diagnostic test for PCOS.

What the appointment may involve

Your doctor may ask about your medical history, examine you and arrange blood tests. These can assess androgen hormones, look for other explanations such as thyroid disease, and check cholesterol or diabetes risk. A GP in the UK may refer you to a gynaecologist or endocrinologist.

Other possible causes of disrupted ovulation include pregnancy, thyroid problems, raised prolactin and substantial changes in weight or exercise. Your clinician chooses tests based on your history. Checking for other causes is part of the assessment, even when PCOS seems possible.

Tell the clinician about hormonal contraception. The combined pill changes hormone measurements and makes androgen blood tests difficult to assess reliably. Ask the prescriber how this affects any proposed testing; do not change prescribed contraception on your own to prepare for a test.

Mention hair removal too. Your account of unwanted hair growth deserves assessment even when the hair is not visible at the appointment. Describe what you remove and where, and how it affects you.

Why adolescent assessment is different

In adolescents, diagnosis requires both persistent menstrual irregularity appropriate to the time since the first period and evidence of higher androgen activity, after other causes are excluded. Ultrasound findings and AMH are not recommended for this diagnosis during adolescence.

The adolescent recommendations specify that ultrasound for the ovarian appearance and AMH are not recommended until 8 years after the first period. This restriction applies to diagnosing PCOS. Symptoms can still be assessed and supported.

Someone with only part of the pattern may be described as “at risk” and offered symptom management with follow-up. That leaves room to review the diagnosis as the pattern becomes clearer. Ask what will be reviewed and how to seek help in the meantime.

The NHS patient page gives a simpler age-based message, saying ultrasound is only done over 18. The international adolescent guidance also considers time since the first period. These are not interchangeable cut-offs, so a birthday alone is not a reason to request an adult scan-based assessment.

Agreeing what happens next

Book a GP appointment (UK), or see your doctor (US or elsewhere), if you think you may have PCOS or symptoms affect everyday life.

After diagnosis, the guideline recommends checking blood glucose status and cholesterol, alongside blood pressure assessment. These checks look at health risks linked to PCOS, separately from the tests used to diagnose it.

Before leaving, ask what supports the diagnosis and which other causes were considered. Ask about anything that remains uncertain. If the answer is “not clear yet”, ask for a follow-up plan and help with the symptoms that brought you in. You can request the explanation in plain language and write down who to contact with further questions.