Polycystic Ovary Syndrome (PCOS)

What happens in PCOS

In PCOS, the ovaries produce more androgens (such as testosterone) than usual. Many people with PCOS also have insulin resistance: the body needs higher insulin levels to keep blood sugar normal, and high insulin further boosts androgen production. Together, these hormone changes stop follicles in the ovaries from maturing and releasing an egg regularly. The immature follicles show up on ultrasound as many small "cysts", which are not true cysts and are harmless.

Symptoms

Symptoms often start around puberty but may appear later, for example after weight gain.

• irregular, infrequent or absent periods
• heavy or prolonged bleeding when periods do come
• excess hair growth (hirsutism) on the face, chest, belly or back
• acne, often on the jaw, chin and upper neck
• thinning scalp hair in a male pattern
• weight gain, especially around the belly, and difficulty losing weight
• difficulty getting pregnant
• dark, velvety skin patches (acanthosis nigricans) in the neck, armpits or groin, a sign of insulin resistance
• skin tags
• mood changes: higher rates of anxiety and depression

Not everyone has all features, and PCOS can occur in people of any body weight.

Causes

The exact cause is not known. PCOS runs strongly in families, and several genes have been linked. Insulin resistance, low-grade inflammation and hormone signaling from the brain all play roles. Weight gain often makes symptoms worse, but PCOS is not caused by being overweight.

Diagnosis

PCOS is usually diagnosed using the Rotterdam criteria, updated in the 2023 international guideline. In adults, you need two of three:

1. irregular or absent ovulation (irregular periods)
2. high androgens: on a blood test, or signs such as excess hair or acne
3. polycystic ovaries on ultrasound or a raised AMH (anti-Mullerian hormone) blood level

In teenagers within 8 years of their first period, both irregular periods and high androgens are needed, and ultrasound is not used, because multiple follicles are normal at this age.

Doctors also rule out other causes with tests such as:

• pregnancy test
• thyroid function
• prolactin
• 17-hydroxyprogesterone (for congenital adrenal hyperplasia)
• cortisol tests if Cushing's syndrome is suspected

Health checks after diagnosis

• blood sugar (HbA1c or glucose tolerance test)
• cholesterol
• blood pressure and weight
• screening for depression, anxiety, eating disorders and sleep apnea

Treatment

Treatment depends on your symptoms and whether you want to become pregnant.

Lifestyle

• healthy eating and regular physical activity improve insulin resistance, periods and ovulation. Losing even 5 to 10 percent of body weight, if overweight, can restore regular cycles
• sleep and stress management
• no single "PCOS diet" is proven best. Choose a pattern you can sustain

Irregular periods and androgen symptoms

• combined birth control pills: regulate periods, protect the womb lining and reduce acne and hair growth
• progestin courses or a hormonal IUD to protect the womb lining if not using the pill
• metformin: improves insulin resistance, can help cycles and weight, especially combined with lifestyle changes
• anti-androgens (spironolactone) for hirsutism and acne, with reliable contraception because they can harm a developing baby
• cosmetic hair removal: laser, electrolysis, and eflornithine cream
• acne treatments

Weight management

Anti-obesity medicines, including GLP-1 receptor agonists, and bariatric surgery are options for some people with PCOS and obesity, discussed with a doctor.

Fertility

• letrozole: the first-choice medicine to trigger ovulation
• clomiphene as an alternative, sometimes with metformin
• gonadotropin injections or IVF if pills do not work
• ovarian drilling, a keyhole procedure, in selected cases

Long-term health risks

• type 2 diabetes and gestational diabetes
• high cholesterol, high blood pressure and heart disease
• endometrial (womb lining) thickening and endometrial cancer, if periods are very infrequent for long periods
• sleep apnea
• fatty liver disease
• depression and anxiety
• pregnancy complications, such as gestational diabetes and preeclampsia

Regular checkups and treatment reduce these risks.

Frequently asked questions

What are the first signs of PCOS?

Common first signs are irregular or missing periods, acne that persists beyond the teens, excess hair on the face or body, thinning scalp hair and weight gain around the belly. Symptoms often begin around puberty.

Can you get pregnant with PCOS?

Yes. Many people with PCOS get pregnant, sometimes naturally and often with help. Lifestyle changes, letrozole to trigger ovulation, and fertility treatments such as IVF are effective. Talk to a doctor if you have not conceived within 12 months, or 6 months if over 35.

Does PCOS go away?

PCOS is a lifelong condition, but symptoms often change over time. Periods may become more regular as you approach menopause, though metabolic risks such as diabetes remain. Treatment keeps symptoms and long-term risks under control.

Do you need cysts on your ovaries to have PCOS?

No. Polycystic-looking ovaries are only one of three criteria. PCOS can be diagnosed with irregular periods and high androgens even if the ovaries look normal. The "cysts" are immature follicles, not true cysts.

What helps PCOS symptoms most?

A combination works best: regular physical activity and healthy eating, birth control pills for periods, acne and hair, metformin for insulin resistance, and targeted treatments for hair growth, acne or fertility. Even modest weight loss can greatly improve symptoms.