PCOS: Symptoms, Causes and Treatment

Written by Dr. Simon Khela MBChB MRCGP, GMC Registered Doctor

Last reviewed: 04-08-2026

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PCOS is one of the most common hormonal conditions I see in general practice, and also one of the most delayed diagnoses. It can take years, and several separate GP visits, for many women to get a clear answer, often because symptoms like irregular periods, acne or excess hair growth get treated individually rather than recognised as part of one underlying picture.

This guide sets out what PCOS actually is, why it develops, the symptoms to recognise, including the bloating some patients call “PCOS belly,”  how it’s diagnosed, and the realistic range of treatments available. It also covers something genuinely new: in May 2026, PCOS was formally given a new name, and it’s worth understanding what that means and why it happened.

What Is PCOS? A Quick Answer

PCOS (polycystic ovary syndrome) is a common hormonal condition affecting how the ovaries work, causing irregular periods, excess androgen (male hormone) effects such as acne or excess hair growth, and, for many women, difficulty conceiving. It’s linked to insulin resistance and affects around 1 in 10 women in the UK, though many remain undiagnosed. There’s no cure, but lifestyle changes, medication and fertility treatment can meaningfully manage symptoms and reduce long-term health risks. In May 2026, PCOS was formally renamed polyendocrine metabolic ovarian syndrome (PMOS) to better reflect its whole-body, hormonal nature; the two terms describe exactly the same condition.

A Note on the Name: PCOS Is Now Also Called PMOS

Many patients are surprised to learn that PCOS has a new official name. In May 2026, following a global consensus process involving more than 50 patient and professional organisations, including the UK charity Verity, polycystic ovary syndrome was renamed polyendocrine metabolic ovarian syndrome (PMOS). The change reflects something clinicians have known for years: most people with the condition don’t actually have ovarian cysts in the traditional sense, and PCOS was always a whole-body hormonal and metabolic condition, not simply an ovarian one.

Because “PCOS” remains by far the more widely recognised and searched term, this guide continues to use it throughout, but don’t be surprised if you start seeing “PMOS” used on the NHS website, by your GP, or by patient charities such as Verity, the UK’s dedicated PCOS charity. They refer to exactly the same condition.

What Causes PCOS?

The exact cause of PCOS isn’t fully understood, but it’s thought to involve a combination of factors:

• Insulin resistance, where the body’s cells don’t respond normally to insulin, leading to higher insulin levels that can increase androgen production
• Raised levels of androgens (male hormones), which affect ovulation and cause many of the visible symptoms
• Genetics: PCOS often runs in families
• Being from a South Asian background, which is associated with a higher likelihood of PCOS

A question I am frequently asked is whether PCOS is caused by being overweight. It isn’t that straightforward; weight and PCOS interact in both directions. Insulin resistance linked to PCOS increases the likelihood of weight gain, and excess weight can, in turn, worsen insulin resistance. Plenty of women with PCOS are a healthy weight, sometimes referred to informally as “lean PCOS.”

Common Symptoms of PCOS

Symptoms usually start around puberty, though some women aren’t diagnosed until their twenties or later, and severity varies enormously between individuals. Common symptoms include:

• Irregular periods, or long gaps between periods
• Excess hair growth (hirsutism), particularly on the face, chest or back
• Hair thinning or hair loss from the scalp
• Weight gain or difficulty losing weight
• Difficulty getting pregnant
• Oily skin and acne
• Persistent tiredness
• Thick, darker patches of skin at the neck or armpits (acanthosis nigricans)
• Low mood, anxiety or other mental health difficulties

Many patients are surprised to learn that PCOS can be present with no symptoms at all, and is sometimes only picked up incidentally during a scan for something else entirely. Patient.info’s PCOS leaflet is a useful, patient-facing summary if you want to read further around how variable the condition can look.

What Is “PCOS Belly”?

One of the most common concerns I see in practice is bloating or a change in body shape that patients describe as their “PCOS belly.” It isn’t a formal medical term, but it’s a genuinely recognised pattern with two main contributors:

• Increased abdominal (visceral) fat, linked to insulin resistance and higher androgen levels, which tend to direct fat storage toward the abdomen rather than the hips and thighs
• Bloating, partly from lower progesterone affecting fluid balance, and partly from PCOS’s associations with gut symptoms such as constipation

It can be uncomfortable and frustrating, but it isn’t dangerous in itself, and it often improves, though not always completely, with the same measures used to manage insulin resistance more broadly.

How Is PCOS Diagnosed?

There’s no single test for PCOS. Diagnosis in adults follows the Rotterdam criteria, set out in NICE clinical guidance, which require at least two of the following three features, alongside ruling out other causes:

• Irregular or absent ovulation, usually shown by infrequent or absent periods
• Clinical or biochemical signs of excess androgens, such as hirsutism or acne, or raised testosterone on a blood test
• Polycystic ovaries on ultrasound: 12 or more small follicles in one or both ovaries, or increased ovarian volume

A typical work-up involves:

• A discussion of your symptoms, periods and family history
• A private blood test to check hormone levels, including testosterone, and markers of insulin resistance
• An ultrasound scan of the ovaries, usually only arranged in adults
• Additional tests to rule out other causes, such as thyroid problems or raised prolactin

One of the most common concerns I see in practice is a patient who’s had a normal ultrasound and assumes this rules PCOS out. It doesn’t; you don’t need visible polycystic ovaries to be diagnosed, and plenty of women with PCOS have a normal scan. If there’s uncertainty, or your case is more complex, a referral to a specialist, usually a gynaecologist or endocrinologist, allows a more detailed assessment.

PCOS Treatment Options

There’s no cure for PCOS, but treatment can meaningfully improve symptoms and reduce long-term risk. The right approach depends on your main symptoms and whether you’re trying to conceive.

Lifestyle Measures (First-Line)

• Eating a balanced diet, with attention to reducing processed and sugary foods that affect insulin levels
• Regular, moderate exercise. NHS guidance specifically notes that very high-intensity exercise can worsen PCOS symptoms for some people, so a sustainable approach tends to work better than an extreme one
• Losing weight if you’re overweight; even a modest reduction of around 5% can meaningfully improve symptoms

Structured support through a weight management programme can make this more achievable than attempting it alone, particularly where insulin resistance is making weight loss harder than usual.

Medicines for PCOS

• The combined pill, progestogen-only pill, or hormonal IUS, to regulate periods and protect the womb lining
• Metformin, a type 2 diabetes medicine used off-label to improve insulin resistance and support weight
• Spironolactone or eflornithine cream to reduce excess hair growth
• Topical or oral treatments for acne

For those who are overweight and haven’t achieved enough change through lifestyle measures alone, weight-loss injections are sometimes considered as part of a wider treatment plan.

Fertility Treatment

PCOS is one of the most common causes of difficulty conceiving, usually because ovulation happens infrequently or not at all. Options include:

• Letrozole or clomifene, medicines that stimulate ovulation
• Metformin, sometimes used alongside fertility medication
• Laparoscopic ovarian drilling, a minor surgical procedure using heat or laser on the ovaries, generally reserved for those who haven’t responded to other treatments

Referral to an infertility clinic is a reasonable next step if initial treatment doesn’t lead to pregnancy within a reasonable timeframe.

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Most women with PCOS who want to conceive do go on to have children, sometimes with support and sometimes without needing any treatment at all  but earlier referral tends to lead to less protracted uncertainty.

Long-Term Health Risks of PCOS

Because PCOS is a metabolic as well as a hormonal condition, it’s linked to a higher risk of several long-term health problems:

• Type 2 diabetes, related to underlying insulin resistance
• High cholesterol and cardiovascular disease
• High blood pressure
• Non-alcoholic fatty liver disease
• A womb (endometrial) cancer risk that’s slightly higher than average, linked to the effect of infrequent periods on the womb lining over time

One of the most common concerns I see in practice is a patient focused entirely on periods or fertility, understandably, while these longer-term risks go undiscussed. Regular checks  including a diabetes test and awareness of the warning signs of high cholesterol  are a genuinely useful part of managing PCOS well beyond the reproductive years.

PCOS and Mental Health

Many patients are surprised to learn how strongly PCOS is linked to mental health. Anxiety and depression are considerably more common in women with PCOS than in the general population, likely reflecting a combination of hormonal effects, visible symptoms such as acne or hair growth, and the frustration of a long or difficult diagnosis. This is a recognised part of the condition, not a personal failing, and a confidential mental health assessment is a legitimate part of managing PCOS well, not a separate issue.

Common Myths About PCOS

• Myth: You need cysts on your ovaries to be diagnosed with PCOS. Fact: The “cysts” seen on ultrasound are actually small, immature follicles, not true cysts  and a normal scan doesn’t rule out PCOS if other criteria are met.
• Myth: PCOS only affects fertility. Fact: It’s a whole-body hormonal and metabolic condition, affecting skin, hair, weight, mental health and long-term disease risk, not just periods and pregnancy.
• Myth: Only women who are overweight get PCOS. Fact: PCOS affects women across the full range of body weights; insulin resistance can occur even at a healthy weight.
• Myth: A PCOS diagnosis means you can’t get pregnant. Fact: Most women with PCOS do go on to conceive, sometimes with fertility treatment and sometimes without.
• Myth: PCOS is caused by an unhealthy lifestyle. Fact: The underlying cause involves genetics and hormones; lifestyle affects how symptoms present, not whether the condition exists in the first place.

When to See a GP

• If your periods are irregular, infrequent, or have stopped altogether
• If you’re noticing excess hair growth, acne, or hair thinning that’s new or worsening
• If you’re struggling to conceive after a year of trying (or sooner if you’re over 35)
• If symptoms are affecting your mental health or day-to-day life
• If you have a family history of PCOS and are concerned about your own symptoms

There’s no need to wait until symptoms feel severe. A private GP appointment can start the conversation and arrange the right initial tests, usually well before a formal diagnosis is confirmed.

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Frequently Asked Questions