What PCOS is, and why its name has changed

PCOS can affect periods, hair growth, fertility and mood. It is a hormone condition, and its effects can reach beyond the reproductive system. The NHS says it can affect anyone who has ovaries.

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.

Why the old name was confusing

The older name focused attention on cysts and ovaries. As the Endocrine Society explains, that left much of this complex hormonal condition out of view. Ovarian cysts are not required for a diagnosis. Some people with PCOS do not have polycystic ovaries at all.

When an ultrasound is relevant, clinicians assess features such as the number of follicles and the size of the ovaries. Those findings are part of a wider assessment. The international guideline also considers how ovulation is working and signs of higher androgen activity, after excluding other causes. A scan description alone cannot confirm PCOS.

The name change has already reached NHS information and the international guideline published by the American Society for Reproductive Medicine. WHO and the US Office on Women’s Health still have pages headed PCOS. Either name in your records or an appointment letter can refer to the same condition.

A common condition with different patterns

WHO estimates that PCOS affects 10–13% of reproductive-aged women. The US Office on Women’s Health gives a different headline estimate: 1 in 10 women of childbearing age. The estimates differ, and neither tells you whether PCOS is causing your symptoms.

Possible symptoms include unpredictable or absent periods, excess facial or body hair, acne and thinning hair on the scalp. Some people have heavy or long periods. Symptoms can change over time, and people with the same diagnosis can have quite different experiences.

A symptom such as acne or irregular periods has other possible explanations too. The NHS advises getting suspected symptoms checked, particularly when they affect everyday life, work or relationships. You can start by describing what has changed.

Hormones, insulin and family links

The cause is not fully understood. Genetics appears to play a part, and PCOS can run in families. WHO also identifies a family history of type 2 diabetes as a risk factor. Family history alone cannot tell you whether someone has PCOS.

Androgens are sometimes described as male hormones, but women make them too. Higher androgen levels can interfere with the release of an egg, called ovulation, and contribute to acne or extra hair growth.

Insulin helps the body use food for energy. Insulin resistance means cells respond less well to it, so insulin levels can rise. It is an important feature of PCOS, but the international guideline does not recommend routine insulin-level tests to guide care. Blood glucose checks serve a different purpose: assessing diabetes risk.

Care that fits your priorities

There is currently no cure, but treatment can improve symptoms and quality of life, support fertility and reduce some longer-term health risks. A care plan can include medicines, support with food and movement, and help with emotional wellbeing. Healthy lifestyle changes have benefits even without weight loss.

Pregnancy can often be achieved naturally or with treatment. Care also matters if you do not want to get pregnant. The international guideline treats PCOS as a lifelong condition, so follow-up also includes health beyond the reproductive years.

Starting a conversation with a clinician

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

In the UK, a GP may arrange assessment with a gynaecologist or endocrinologist. In the US, your doctor can discuss your medical history, examine you and arrange tests to rule out other causes. Elsewhere, start with your usual primary care clinician.

Start with the change that matters most to you. Bring any dates you know and questions about what happens next. You could begin with, “My periods have changed, and I’d like to understand what needs checking.” Ask which part of the plan addresses your immediate concern and which part is longer-term follow-up.