Before you use this guide
This is general information, not a diagnosis or a substitute for care from a clinician who knows your medical history. Seek urgent help for severe or rapidly worsening symptoms.
PCOS is a clinical syndrome, not one result
Polycystic ovary syndrome (PCOS) can affect periods, ovulation, hair growth, skin, fertility and metabolic health. The NHS now uses the term polyendocrine metabolic ovarian syndrome (PMOS), reflecting that the condition involves more than the appearance of the ovaries.
There is no single marker that confirms or excludes it. Assessment combines symptoms and menstrual history with evidence of androgen excess, and—when appropriate—ultrasound findings, while other causes are considered.
What blood tests may be considered?
Testing may include hormones such as testosterone and sex hormone-binding globulin, with other tests selected to investigate irregular periods or androgen-related symptoms. Thyroid and prolactin testing may help exclude alternative explanations in the right clinical context.
A clinician may also assess glucose regulation and cholesterol because PCOS can be associated with insulin resistance and increased longer-term metabolic risk. The exact panel should be tailored rather than copied from a generic checklist.
Factors that affect interpretation
Hormonal contraception, fertility treatment, medication, supplements, cycle timing and recent illness can influence results. Tell the clinician or testing service what you take and record your bleeding pattern.
Symptoms associated with PCOS are common and can have other causes. An abnormal androgen result needs clinical context, while a normal result does not automatically explain irregular cycles or fertility difficulty.
What happens after testing?
If PCOS is suspected, next steps depend on your priorities—cycle management, skin or hair symptoms, fertility, weight, emotional wellbeing or prevention of longer-term health problems. Results should lead to an individual plan, not simply a label.
Regular follow-up may include blood pressure and metabolic risk assessment. Seek medical advice if periods are very infrequent, symptoms are worsening or you are having difficulty becoming pregnant.
What to bring to an appointment
- A record of period dates and typical cycle length.
- Details of acne, hair growth, scalp hair loss or weight change.
- Current contraception, medication and supplements.
- Any fertility plans or pregnancy possibility.
- Relevant personal and family history, including diabetes.
Common questions
Questions about this topic.
No. Blood tests may support the assessment and exclude other causes, but diagnosis considers symptoms, menstrual or ovulatory patterns and sometimes ultrasound findings.
Sources and further reading
We use authoritative UK guidance and patient information. External sources may be updated after this guide is published.
