PCOS: symptoms, diagnosis and treatment options explained
Quick answer
PCOS (polycystic ovary syndrome) is a common hormonal condition affecting how the ovaries work. It's diagnosed when at least two of three features are present: irregular ovulation, higher androgen levels, and polycystic ovaries on a scan. There's no cure, but symptoms such as irregular periods, acne and unwanted hair growth can usually be managed with lifestyle changes and treatment.
What is PCOS?
Polycystic ovary syndrome (PCOS) is a common hormonal condition that affects how the ovaries work. It's thought to affect around one in ten women of reproductive age in the UK, though many people go undiagnosed for years because the symptoms vary so widely from person to person.
The name can be misleading. PCOS is not the same as having ovarian cysts in the everyday sense. On an ultrasound scan, the ovaries may show a number of small, fluid-filled follicles arranged around the edge, sometimes described as a "string of pearls" appearance. Not everyone with PCOS has this feature, and having it alone does not mean you have the condition.
Common symptoms of PCOS
PCOS symptoms usually start in the late teens or twenties, though they can appear later in life, and they often become more noticeable around the time periods should be settling into a regular pattern. The areas most commonly affected are periods, skin and hair, and weight, but the mix and severity differs from one person to the next, which is part of why PCOS can take time to recognise.
- Irregular or absent periods: cycles longer than 35 days, fewer than eight periods a year, or periods that stop altogether.
- Acne and oily skin: breakouts that can be more persistent than typical teenage acne, often along the jawline and chin.
- Excess hair growth (hirsutism): thicker, darker hair on the face, chest, back or abdomen, caused by higher androgen (male hormone) levels.
- Scalp hair thinning: a male-pattern style of thinning, often more noticeable at the crown.
- Weight changes: difficulty losing weight, or weight gain concentrated around the abdomen.
- Fertility difficulties: irregular or absent ovulation can make conceiving take longer.
Not everyone experiences every symptom, and severity varies considerably from person to person. Some people are diagnosed after finding it difficult to conceive; others notice skin or hair changes first.
What causes PCOS?
The exact cause of PCOS is not fully understood, and it's likely that several factors act together rather than any single one explaining every case.
Insulin resistance. Many people with PCOS have some degree of insulin resistance, meaning the body needs to produce more insulin to keep blood sugar stable. Higher insulin levels can, in turn, encourage the ovaries to produce more androgens.
Hormone imbalance. Raised androgen levels, and a higher ratio of luteinising hormone (LH) to follicle-stimulating hormone (FSH), can disrupt ovulation.
Genetics. PCOS tends to run in families. If a mother or sister has PCOS, the likelihood of developing it is higher.
PCOS is not caused by anything a person has done. It is not related to lifestyle choices or the number of sexual partners a person has had.
How PCOS is diagnosed
There is no single test for PCOS. In the UK, diagnosis usually follows what's known as the Rotterdam criteria: at least two of the following three features need to be present, once other conditions with similar symptoms (such as thyroid problems or high prolactin) have been ruled out.
A diagnosis usually involves a discussion of your symptoms and medical history, a blood test to check hormone levels (including testosterone and the LH to FSH ratio) and rule out other causes, and sometimes an ultrasound scan of the ovaries. A scan is not always needed, particularly if the other two criteria are already met.
Related health considerations
Because PCOS is linked to insulin resistance, it is associated with a higher long-term likelihood of type 2 diabetes and raised cholesterol, so many clinicians recommend periodic blood tests to keep an eye on these alongside PCOS itself, particularly if there is also a family history of diabetes or heart disease.
Irregular ovulation also means the lining of the womb can build up without being shed regularly. This is why some people with infrequent periods are advised to take a hormonal treatment, such as the combined pill, to help manage the womb lining.
PCOS can affect fertility because ovulation is irregular or absent, but many people with PCOS do go on to conceive, sometimes with support such as ovulation-inducing medication prescribed by a specialist. Sleep can also be affected: broken or poor-quality sleep, including a higher likelihood of sleep apnoea, is reported more often in people with PCOS, and is worth mentioning to a clinician if you're regularly waking tired.
Living with PCOS
A diagnosis can bring relief, an explanation for symptoms that may have been dismissed for years, but it can also feel overwhelming. Visible symptoms such as acne, hair growth or weight changes are often the hardest to live with day to day, and it's common for mood, confidence and body image to be affected alongside the physical symptoms. If you're finding this side of things difficult, it's worth raising with your GP or clinician too, since support is available and you don't need to manage it alone.
Because PCOS is a long-term condition rather than something that resolves on its own, most people benefit from periodic review rather than a single one-off consultation, so that treatment can be adjusted as symptoms, priorities or plans (such as starting a family) change over time.
Treatment and management options
There is no cure for PCOS, so treatment focuses on managing individual symptoms and reducing longer-term health considerations.
- Lifestyle measures: regular activity and a balanced diet can improve insulin sensitivity and, for some people, help regulate cycles, even without significant weight change; small, sustainable changes tend to be easier to maintain than strict short-term plans.
- Cycle regulation: a combined hormonal pill, such as the combined contraceptive pill, is often used to bring on regular periods and help protect the womb lining, and can also improve acne and excess hair growth for some people.
- Skin and hair symptoms: options for acne and excess hair growth are covered in our guides to acne treatment and managing unwanted hair growth.
- Fertility support: if you are trying to conceive, a GP or fertility specialist can discuss options for encouraging regular ovulation.
Treatment is individual. What helps one person's symptoms may not suit another, which is why an initial consultation and, where useful, hormone blood testing are a sensible starting point, with the plan reviewed and adjusted as things change.
When to seek help
Speak to a GP or clinician if your periods are irregular, infrequent or have stopped, if you notice new or worsening acne or hair growth, or if you have been trying to conceive for 12 months (or six months if you are over 35) without success.
Because PCOS symptoms overlap with other hormonal conditions, getting the right blood tests is an important first step towards an accurate diagnosis and a treatment plan that fits your situation.
Frequently asked questions
Can PCOS be cured?
No, there's no cure for PCOS, but symptoms such as irregular periods, acne and excess hair growth can usually be managed with lifestyle changes, hormonal treatment or a combination of both, tailored to what matters most to you.
Do I need an ultrasound scan to be diagnosed with PCOS?
Not always. Diagnosis in the UK is based on meeting two of three Rotterdam criteria: irregular ovulation, signs of higher androgen levels, and polycystic ovaries on a scan. If the first two are already confirmed by your symptoms and a blood test, a scan may not be needed.
Does PCOS always affect fertility?
Not always. PCOS can make ovulation irregular or infrequent, which can make conceiving take longer, but many people with PCOS go on to have children, sometimes with support to encourage regular ovulation.
Why does PCOS cause weight gain?
PCOS is linked to insulin resistance, which can make weight harder to lose and easier to regain. Not everyone with PCOS gains weight, and weight alone does not confirm or rule out the condition.
What blood tests check for PCOS?
Blood tests usually look at testosterone and other androgens, the ratio of LH to FSH, and markers that rule out thyroid or prolactin problems, which can cause similar symptoms.
Is PCOS the same as having cysts on your ovaries?
No. Despite the name, PCOS is a hormonal condition, and the small follicles sometimes seen on an ultrasound are not the same as ovarian cysts. Some people with PCOS have normal-looking ovaries on a scan.