What PCOS is, and why its name has changed

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

PCOS now has a new name: polyendocrine metabolic ovarian syndrome (PMOS). Both names mean the same condition. This article uses PCOS because it’s the name you may already know.

Why the old name was confusing

The old name put the focus on cysts and ovaries. As the Endocrine Society explains, that left out much of what this complex hormone condition involves. You don’t need ovarian cysts to be diagnosed. Some people with PCOS don’t have polycystic ovaries at all.

When a scan is useful, clinicians look at things like the number of follicles (small sacs where eggs grow) and the size of the ovaries. These findings are one part of a wider check. Once other causes are ruled out, the international guideline also looks at how ovulation is working and signs of higher androgen activity. A scan report alone can’t confirm PCOS.

The new name is already used in NHS information and in 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 mean the same condition.

A common condition with different patterns

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

Possible symptoms include periods that are hard to predict or have stopped, extra hair on the face or body, acne and thinning hair on the scalp. Some people have heavy or long periods. Symptoms can change over time. People with the same diagnosis can have quite different experiences.

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

Hormones, insulin and family links

The cause isn’t fully understood. Genes seem to play a part, and PCOS can run in families. WHO also names a family history of type 2 diabetes as a risk factor. Family history alone can’t tell you whether someone has PCOS.

Androgens are sometimes called male hormones, but women make them too. Higher androgen levels can get in the way of ovulation (the release of an egg), and can lead to acne or extra hair growth.

Insulin helps the body use food for energy. Insulin resistance means the body’s cells respond less well to it, so insulin levels can rise. It’s an important feature of PCOS. But the international guideline doesn’t recommend routine insulin tests to guide care. Blood sugar checks do a different job: they look at your risk of diabetes.

Care that fits your priorities

There’s no cure at the moment, but treatment can ease symptoms, improve quality of life, support fertility and lower some longer-term health risks. A care plan can include medicines, support with food and movement, and help with emotional wellbeing. Healthy changes to your lifestyle have benefits even if you don’t lose weight.

Many people with PCOS get pregnant, naturally or with treatment. Care matters too if you don’t want to get pregnant. The international guideline treats PCOS as a lifelong condition, so follow-up also looks at your health beyond the years when you can have children.

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 your symptoms affect everyday life.

In the UK, a GP may arrange for you to see a gynaecologist or a hormone specialist (endocrinologist). In the US, your doctor can ask about your medical history, examine you and arrange tests to rule out other causes. Elsewhere, start with your usual doctor or clinic.

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 deals with your immediate worry and which part is longer-term follow-up.