Guide
What Is PCOS? A Plain-Language Guide to Polycystic Ovary Syndrome
PCOS is a common hormone and metabolic condition affecting roughly 1 in 8 to 1 in 10 women. Here is what is going on in the body, how it is diagnosed, what it is not, and what helps by goal.
By PCOS Polly ·
Key takeaways
- PCOS is a common hormone and metabolic condition, affecting roughly 1 in 8 to 1 in 10 women, that links irregular ovulation, higher androgen activity, and often insulin resistance.
- It is a syndrome: different people get different mixes of cycle, skin and hair, metabolic, and fertility symptoms.
- Adults are diagnosed with 2 of 3 features after look-alike conditions are ruled out.
- You can have PCOS at any body size, and the ovarian 'cysts' are really immature follicles.
- In 2026, experts renamed it polyendocrine metabolic ovarian syndrome (PMOS); the diagnosis and treatments are unchanged.
PCOS (polycystic ovary syndrome) is a common hormone and metabolic condition, affecting roughly 1 in 8 to 1 in 10 women and people with ovaries. It links three things: irregular ovulation, higher androgen activity, and often insulin resistance. It is a syndrome, so different people get different mixes of cycle, skin and hair, metabolic, and fertility issues. Adults are diagnosed with 2 of 3 key features after look-alike conditions are ruled out.
In May 2026, a global expert consensus renamed the condition polyendocrine metabolic ovarian syndrome (PMOS). It is the same condition with the same diagnosis and treatments; read what the PMOS name change means.
What is actually going on in the body
| Feature | What happens | What you might notice |
|---|---|---|
| Irregular ovulation | Follicles start, stall, or do not release an egg on a predictable schedule | Long, short, or missing periods; harder pregnancy timing |
| Higher androgens | Androgens run higher, or skin and hair are more sensitive to them | Acne, facial or body hair, scalp thinning |
| Insulin resistance | Cells respond less to insulin, so the pancreas makes more | Cravings, energy dips, weight changes; higher insulin can push the ovaries to make more androgens |
You can have PCOS at any body size (see lean PCOS). The “cysts” on ultrasound are usually many small follicles, not large painful cysts, and an ultrasound alone does not mean you have PCOS.
How PCOS is diagnosed in adults
Clinicians look for 2 of these 3, after ruling out look-alikes such as thyroid problems or high prolactin:
- Irregular cycles or ovulation problems
- Clinical or lab signs of high androgens
- Polycystic-looking ovaries on ultrasound, or a high AMH level (added in the 2023 guideline)
If you already have irregular cycles and androgen signs, an ultrasound or AMH test is often unnecessary. Teens are diagnosed differently; see PCOS in teens. Full details are in how PCOS is diagnosed, and the PCOS symptoms guide has a self-check list.
What PCOS is not
- Not your fault, and not solved by “just eat less”
- Not automatic infertility: many people conceive, and some need help ovulating
- Not the same as endometriosis
- Not cured by one supplement, but symptoms are highly manageable
What usually helps, by goal
| Goal | Options people commonly discuss with clinicians |
|---|---|
| Regular cycles and protecting the uterine lining | Hormonal contraception, or planned progestin-induced bleeds if periods are rare (irregular periods) |
| Skin and hair | Combined pills, dermatology care, laser, and in some cases anti-androgens (facial hair, hair loss) |
| Insulin and metabolism | Protein-forward meals, walking after eating, strength training, sleep; metformin when indicated (insulin resistance) |
| Fertility | Ovulation tracking; letrozole is the guideline-preferred first medication for ovulation induction (getting pregnant with PCOS) |
| Mood | Screening and support for anxiety and depression, which are more common with PCOS (PCOS and mental health) |
Living with PCOS
Treat PCOS as a long-game health pattern. Track what flares your symptoms, get glucose and cholesterol checked over time, and pick one or two levers that match your top goals rather than a 20-step overhaul.
PCOS Polly helps you log cycles, symptoms, meals, and habits so patterns and progress become visible. Browse more guides on the PCOS Polly blog.
Sources
- Teede HJ et al. 2023 International Evidence-based Guideline for the Assessment and Management of PCOS.
- Teede H et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet, 2026.
- Mayo Clinic. Polycystic ovary syndrome (PCOS): symptoms and causes.
- Cleveland Clinic. Polycystic ovary syndrome (PCOS).
This article is for general information and is not medical advice.
Frequently asked questions
What is PCOS in simple terms? +
PCOS is a common hormone and metabolic condition in which ovulation is irregular, androgens such as testosterone run higher or have a stronger effect, and insulin often works less efficiently. Together these can cause irregular periods, acne, unwanted hair, scalp thinning, weight changes, and difficulty getting pregnant.
What causes PCOS? +
There is no single known cause. PCOS runs in families, and genetics, insulin resistance, and hormone signaling between the brain and ovaries all play a role. Lifestyle factors can make symptoms better or worse, but PCOS is not caused by anything you did.
Can PCOS be cured? +
There is no cure, but symptoms are highly manageable. Treatment is chosen by goal, such as regulating cycles, improving skin and hair, managing insulin resistance, or supporting fertility, and many people find symptoms change across life stages.
Do you have to have cysts to have PCOS? +
No. The 'cysts' seen on ultrasound are usually many small immature follicles, not true cysts, and polycystic-looking ovaries are only one of three diagnostic features. Many people are diagnosed based on irregular cycles and signs of high androgens alone.
Is PCOS the same as endometriosis? +
No. PCOS is a hormone and metabolic condition centered on ovulation and androgens, while endometriosis is a condition in which tissue similar to the uterine lining grows outside the uterus and often causes significant pain. Some people have both.
Keep reading
All articles →-
GuideHow PCOS Is Diagnosed: Criteria, Blood Tests, and What to Ask Your Doctor
Adults are diagnosed with PCOS when they meet 2 of 3 criteria after other causes are ruled out. Here is how the criteria work, which blood tests and scans are used and why, and questions to bring to your appointment.
Read article -
GuideLean PCOS: Can You Have PCOS If You're Thin?
Yes, you can have PCOS at a normal or low BMI. Lean PCOS is a descriptive label, not a separate disease. Here is how it is diagnosed, how it can feel different, which labs still matter, and what tends to help.
Read article -
GuidePCOS in Teens: Signs, Diagnosis, and What Parents Should Know
Teen PCOS is easy to over- or under-diagnose because cycles are naturally irregular after periods start. Here are the age-specific signs, how diagnosis differs for teens, treatment building blocks, and tips for parents.
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