How do I know if I have PCOS for sure?

If you suspect you may have PCOS, the most important step is to speak with your GP. PCOS is what’s called a diagnosis of exclusion – this means other conditions need to be ruled out first. Only a healthcare professional can make the diagnosis, so it’s important to get checked rather than relying on self-assessment.

Things to reflect on before seeing your GP

While you cannot diagnose PCOS yourself, thinking about your symptoms can help you prepare for the appointment. For example:

• If you’re not on hormonal contraception, are your periods irregular or sometimes absent?
• Do you experience excess hair growth on your face or body, or persistent acne?
• Have you noticed recent weight changes that don’t seem linked to diet or lifestyle?
• Do other women in your family have a PCOS diagnosis?

If you answered “yes” to some of these questions, it may be worth discussing them with your GP.

Keeping a symptoms diary

Before your appointment, it can be useful to keep a record of your symptoms. This can help you and your GP look for patterns. You might want to note:

• Period dates, cycle length, and how heavy or light they are
• Whether ovulation is absent (if you’re tracking with ovulation kits or trying to conceive)
• Weight changes
• Excess hair growth (face, chest, stomach, thighs, etc.)
• Thinning hair on the head
• Acne or oily skin
• Skin changes such as tags or dark, velvety patches (known as acanthosis nigricans)
• Mood changes, anxiety, low mood, or worsening PMS
• Fertility challenges or recurrent miscarriage
• Fatigue or low energy

What guidelines say about diagnosis

According to current NICE guidance:

In adults (over 20 years old), a diagnosis of PCOS may be considered if two out of the following three are present, once other causes have been ruled out:

• Signs of high androgen levels (either clinical or shown in blood tests)
• Ovulatory dysfunction (irregular or absent periods)
• Polycystic ovarian appearance on ultrasound

Or, put more simply:

• A blood test showing raised androgens
• Irregular or absent periods
• Multiple “cysts” on ovaries visible on ultrasound

In adolescents (under 20 years old), diagnosis is based on hormone levels and irregular or absent periods. Ultrasound is not usually recommended at this stage, as it is not considered reliable for diagnosis in younger women.

Adolescents with some PCOS features, but who do not meet the full diagnostic criteria, may be considered at increased risk. Guidelines suggest reassessment at or before full reproductive maturity (approximately eight years after the first period).

Depending on your age and symptoms, your GP may recommend blood tests and/or an ultrasound scan as part of the diagnostic process.

Important note
Nutrition and lifestyle approaches can support general wellbeing if you have PCOS symptoms, but they cannot replace medical diagnosis or treatment. Always seek advice from your GP if you are concerned about your symptoms.