PCOS: Symptoms, Causes, Diagnosis & Treatment

If you have been told you have polycystic ovary syndrome (PCOS) — or you suspect you might — this guide walks you through what it is, how it shows up, how it is diagnosed and, most importantly, what you can actually do about it. PCOS is common, manageable, and very much something you can live well with. It is not a life sentence, and it is not your fault.

What is PCOS?

PCOS (polycystic ovary syndrome) is a hormonal condition that affects how the ovaries work. It is one of the most common hormonal disorders in women of reproductive age, affecting roughly 1 in 10. Despite the name, you do not need to have "cysts" on your ovaries to have PCOS — the term is slightly misleading. What the follicles seen on an ultrasound actually represent are small, immature egg sacs that have not been released as they normally would during ovulation.

At its core, PCOS is driven by an imbalance in reproductive hormones and, very often, by insulin resistance — a state in which the body's cells respond less efficiently to insulin. These two threads — hormones and insulin — explain almost every symptom of the condition and almost every strategy for managing it.

Common symptoms

PCOS looks different from one woman to the next, which is part of why it is so often missed. The most common signs include:

• Irregular, infrequent or absent periods — the single most common sign, caused by inconsistent or absent ovulation. For a deeper look, see our guide to irregular periods with PCOS.
• Acne and oily skin, often along the jaw, chin and back — driven by higher androgen levels. Our PCOS and acne guide covers what helps.
• Excess hair growth (hirsutism) on the face, chest or stomach, and sometimes thinning scalp hair.
• Weight changes and difficulty losing weight, which are closely tied to insulin resistance.
• Difficulty conceiving, because ovulation is irregular — explored in PCOS and fertility.

You do not need every symptom to have PCOS. Many women have just two or three. If several of these sound familiar, it is worth a conversation with your doctor. See our full PCOS symptoms checklist to take to that appointment.

What causes PCOS?

The exact cause is not fully understood, but three factors are well established and tend to reinforce one another.

Insulin resistance

Most women with PCOS have some degree of insulin resistance. When cells respond poorly to insulin, the body produces more of it to compensate. High insulin levels, in turn, prompt the ovaries to produce more androgens — the hormones responsible for acne and excess hair. This is why managing insulin is central to managing PCOS, and why understanding the root causes matters.

Hormonal imbalance

Higher-than-typical androgen levels disrupt the normal signals that trigger ovulation, leading to the irregular cycles that define the condition.

Genetics

PCOS tends to run in families. If your mother or sister has it, your own likelihood is higher — though genes are not destiny, and lifestyle still makes a meaningful difference.

How PCOS is diagnosed

There is no single test for PCOS. Doctors usually use the Rotterdam criteria, which require at least two of the following three findings: irregular or absent ovulation; clinical or blood-test signs of high androgens; and polycystic ovaries on ultrasound. Crucially, other conditions that can mimic PCOS — such as thyroid problems or high prolactin — must be ruled out first. Our detailed PCOS diagnosis guide explains each step and what the blood tests mean.

Treatment and management

There is no cure for PCOS, but the symptoms are highly manageable — and management is usually built from the same foundations, then tailored to your priorities (for example, fertility versus skin versus cycle regularity).

Lifestyle foundations

For most women, the first and most powerful lever is lifestyle. A balanced, lower-glycaemic eating pattern, regular movement and adequate sleep all improve insulin sensitivity, which addresses the condition at its root. Even modest changes can restore more regular cycles. Our PCOS diet guide and weight management guide go into the practical detail.

Medication

Where lifestyle alone is not enough, doctors may suggest medication. Hormonal contraception can regulate cycles and improve acne and excess hair. Insulin-sensitising medication is sometimes used to address the metabolic side. For women trying to conceive, specific medications can help induce ovulation. The right choice depends entirely on your goals — which is a conversation to have with your clinician.

Targeted symptom care

Acne, excess hair and hair thinning each have their own evidence-based treatments that can be layered on top of the foundational work. None of this has to be tackled all at once.

PCOS and fertility

A common fear after a PCOS diagnosis is that pregnancy will be impossible. It is not. PCOS is one of the most common — and most treatable — causes of difficulty conceiving. Many women with PCOS conceive naturally, and many more with support. Read PCOS and fertility for what the path can look like.

PCOS and your long-term health

PCOS is more than a reproductive condition — because it is rooted in how your body handles insulin, it carries some longer-term health considerations that are worth understanding so you can stay ahead of them. The good news is that the same lifestyle foundations that ease day-to-day symptoms also protect your future health.

Women with PCOS have a higher risk of developing type 2 diabetes, because insulin resistance is so central to the condition. Many doctors recommend periodic blood-sugar checks, and the dietary and movement habits that improve PCOS symptoms also meaningfully lower this risk. There is also a modestly raised risk of high blood pressure and unfavourable cholesterol, so heart-healthy habits do double duty. Finally, because irregular cycles can mean the womb lining is not shed regularly, some women with PCOS have a higher risk of endometrial changes over the long term — which is one reason doctors often want to ensure you have several periods a year, sometimes with the help of medication. None of these risks are a foregone conclusion; they are reasons to stay engaged with your care, not reasons to worry.

PCOS and mental health

The emotional side of PCOS is real and often under-discussed. Living with symptoms such as acne, unwanted hair, weight changes or fertility worries can take a toll on self-esteem, and rates of anxiety and low mood are higher among women with PCOS — partly because of the hormonal and metabolic changes themselves, and partly because of the daily reality of managing a chronic condition. If you notice your mood dipping, please treat it as seriously as any physical symptom. The strategies in our guide to managing anxiety can help, and there is no shame in seeking support. Caring for your mental health is part of caring for your PCOS, not separate from it.

Tracking your cycle and symptoms

One of the most useful habits you can build is simple tracking. Noting your periods, symptoms, energy and mood over a few months gives you and your doctor a clearer picture than memory ever can, and it helps you see whether the changes you make are working. You do not need anything fancy — a notes app or a paper diary is enough. Record the first day of each period, any symptoms that bother you, and anything you have changed in your diet, movement or medication. Patterns that are invisible week to week often become obvious across a few months, and that information makes every appointment more productive.

Common myths about PCOS

Plenty of misinformation surrounds PCOS, and untangling it is genuinely reassuring. "You caused it by being overweight" is false — PCOS occurs across all body types, and while weight can influence symptoms, it is not the cause. "You can't get pregnant with PCOS" is also false, as covered above. "You must have cysts to have PCOS" is misleading; the diagnosis does not require them. And "PCOS goes away after menopause" is only partly true — periods stop, but the metabolic aspects can continue, so the healthy habits remain worthwhile for life. Being able to recognise these myths protects you from unnecessary guilt and from advice that will not help.

Questions worth asking your doctor

Appointments are short, so it helps to arrive prepared. Useful questions include: which of my symptoms should I prioritise treating first? Should I have my blood sugar and cholesterol checked? Given my goals — whether that is regular cycles, clearer skin or trying to conceive — what would you suggest first? And how long should I expect to wait before we know whether a change is working? Bringing your symptom tracking and our symptoms checklist turns a rushed appointment into a genuinely useful one.

Living well with PCOS

PCOS is a long-term condition, but it responds well to steady, consistent care. The goal is not perfection — it is a sustainable set of habits that keep insulin and hormones in a healthier range, plus targeted help for whichever symptoms bother you most. Work with a clinician you trust, make changes you can actually maintain, and be patient: cycles and symptoms often take a few months to respond. Thousands of women live full, healthy lives with PCOS — with the right knowledge and support, you can be one of them.