I have had a few patients ask me to help them clarify whether they have polycystic ovary syndrome (PCOS). It can be confusing! So, let’s talk about PCOS and how it’s diagnosed.
Polycystic ovary syndrome (PCOS) is a common hormone condition that affects about one in eight women. Despite the name, PCOS is not just about ovaries or cysts, and diagnosis is not based on a single test. PCOS affects hormones, metabolism, mental health and long‑term wellbeing, and symptoms can change at different life stages.
Doctors diagnose PCOS by looking at a pattern of symptoms, blood tests, and sometimes scans, using international guidelines developed by experts at Monash University and around the world. You can access the guideline here (insert hyperlink: https://www.monash.edu/medicine/mchri/pcos/guideline), if you’re interested.
There is no single ‘PCOS Test’, instead PCOS is diagnosed when a person has two out of three key features:
1. Irregular periods
This can include, periods that come far apart, are very unpredictable, or no periods at all. This usually means ovulation is not happening regularly.
2. Signs of higher androgen (“hormone”) levels
These hormones are often thought of as “male‑type” hormones, but everyone has them. Signs of high androgen levels can include increased hair growth on your body or face, acne that is persistent, and thinning hair on the scalp.
3. Polycystic‑looking ovaries
Some people with PCOS have ovaries that look different on an ultrasound because they have more follicles than we normally expect to see. In adults, a blood test called AMH can sometimes be used instead of a scan. Importantly, you do not need cysts/follicles to have PCOS and many people with PCOS have completely normal‑looking ovaries.
Before diagnosing PCOS, doctors check for other causes of irregular periods or hormone changes. This is an important part of diagnosing you safely and accurately.
It’s also important to know that PCOS can be harder to diagnose in teenagers because irregular periods and acne are common during puberty. The diagnostic criteria are different so that we avoid labelling teenagers too early.
Understanding whether you have PCOS can help explain symptoms that may have been present for years, guide more personalised care, and support better long‑term health planning. If you think PCOS may be relevant for you, a GP, gynaecologist or endocrinologist can help you work through the diagnostic process.
