Polycystic ovary syndrome (PCOS) is a common hormonal condition that causes irregular or absent periods, signs of excess male hormones such as acne and extra hair growth, and often difficulty getting pregnant. It affects roughly 1 in 10 women of reproductive age, and many are not diagnosed. Despite the name, you do not need cysts on your ovaries to have PCOS.
Signs and symptoms of PCOS
- Irregular, infrequent or absent periods
- Difficulty getting pregnant because ovulation is irregular
- Excess hair on the face, chest, back or tummy (hirsutism)
- Acne and oily skin
- Thinning hair on the scalp
- Weight gain, especially around the waist
- Dark, velvety skin in the neck, armpits or groin (acanthosis nigricans), a sign of insulin resistance
How PCOS is diagnosed
Doctors usually use the Rotterdam criteria. You need two of these three, after other causes have been ruled out:
- Irregular or no ovulation (irregular periods)
- Signs of high androgens, on examination or blood test
- Polycystic ovaries on ultrasound
Blood tests may include testosterone, prolactin, thyroid function, and checks for diabetes and cholesterol. In adolescents, ultrasound is not used for diagnosis because many normal teenage ovaries look polycystic.
What causes PCOS?
The cause is not fully known. It runs in families and is closely linked to insulin resistance, where the body needs more insulin to control blood sugar. High insulin pushes the ovaries to make more testosterone, which disrupts ovulation.
Treatment options
- Lifestyle: for women who are overweight, losing even 5% of body weight can make periods more regular and improve fertility. Regular exercise helps insulin resistance at any weight.
- Irregular periods: the combined contraceptive pill or regular progestogen courses protect the womb lining.
- Acne and excess hair: the combined pill, topical treatments, and sometimes anti-androgen medicines; hair removal methods.
- Insulin resistance: metformin may be prescribed.
- Fertility: letrozole is now commonly used first to trigger ovulation; clomifene, gonadotropins or IVF are other options under a specialist.
Can you get pregnant with PCOS?
Yes. Many women with PCOS get pregnant naturally or with simple ovulation treatment. Tracking periods, keeping a healthy weight and seeking help after 6 to 12 months of trying (sooner if periods are absent or you are over 35) give the best chance. In pregnancy, women with PCOS have a higher risk of gestational diabetes, pre-eclampsia and preterm birth, so they need good antenatal care.
Long-term health risks
- Type 2 diabetes and gestational diabetes
- High blood pressure and high cholesterol
- Sleep apnoea
- Endometrial (womb lining) thickening and cancer if periods are very infrequent
- Depression and anxiety
Nursing and midwifery tips
- Ask about period frequency when women attend for acne, weight or fertility concerns.
- Offer blood pressure checks and diabetes screening.
- Be sensitive: hair growth, weight and infertility can affect self-esteem and relationships.
- Warn against expensive unproven “PCOS cures”.
Frequently asked questions
Can PCOS be cured?
There is no cure, but symptoms can be well controlled and many women have children.
Does PCOS cause weight gain?
It can make weight gain easier and weight loss harder because of insulin resistance, but not everyone with PCOS is overweight.
Is PCOS the same as having ovarian cysts?
No. The “cysts” in PCOS are small immature follicles, not true cysts, and some women with PCOS have normal-looking ovaries.
Related reading: Fibroids: symptoms and treatment · Infertility: supporting each other · Gestational diabetes screening
Checked against NHS guidance on PCOS. Updated 5 November 2026. This guide is for education and does not replace advice from your doctor.