Roughly 1 in 8 adult women worldwide has polycystic ovary syndrome, making it the most common hormonal disorder among women of reproductive age. Using the most widely accepted diagnostic standard, global prevalence sits at about 12%, which translates to hundreds of millions of women. In the United States alone, the CDC estimates PCOS affects as many as 5 million women. Perhaps most striking: up to 70% of women living with PCOS don’t know they have it.
Global Prevalence by the Numbers
A 2025 systematic review and meta-analysis published in Human Reproduction Update pooled data from studies around the world and found that 12.1% of adult women meet the criteria for PCOS under the Rotterdam diagnostic standard, the one most commonly used in clinical practice. That percentage shifts depending on which diagnostic criteria researchers apply. Using stricter criteria from the National Institutes of Health, the rate drops to 7.9%. Using criteria focused on excess androgen levels (male hormones like testosterone), it rises to 12.7%.
When women are simply asked whether they’ve been told they have PCOS, only 7.8% say yes. That gap between the clinical rate and the self-reported rate underscores how many cases go unrecognized. The World Health Organization puts the underdiagnosis figure starkly: an estimated 70% of affected women worldwide have never been diagnosed.
Why the Numbers Vary So Much
PCOS doesn’t have a single blood test or scan that confirms it. Instead, doctors look for a combination of signs: irregular or absent periods, elevated androgen levels (which can show up as excess facial hair, acne, or thinning scalp hair), and a characteristic appearance of the ovaries on ultrasound. The Rotterdam criteria require any two of those three features. The older NIH criteria are narrower, requiring both irregular periods and high androgens, which naturally captures fewer women. This is why you’ll see prevalence estimates ranging from about 8% to 13% depending on the source. The condition itself hasn’t changed; the diagnostic net is just wider or narrower.
For adolescents, diagnosis is even trickier because irregular periods and acne are common during puberty regardless of PCOS. Global prevalence among teenagers comes in around 6% to 10%, depending on criteria. Rates vary by region too, from roughly 3% in the Western Pacific to over 11% in South-East Asia.
Who Is Most Affected
PCOS occurs across all racial and ethnic backgrounds, but the burden isn’t evenly distributed. A Kaiser Permanente study of U.S. adolescents found that among those with obesity, Asian and Pacific Islander teens had about twice the risk of PCOS compared to white teens, while Hispanic and Latina teens had about 1.3 times the risk. Black adolescents in the study had the lowest prevalence among those with obesity, at 2.1%, compared to 4.2% for Asian and Pacific Islander teens.
These numbers come with an important caveat. Diagnosis rates are shaped by access to healthcare, cultural attitudes around menstrual health, and whether a provider thinks to screen for the condition. Groups with less access to specialists or those where period irregularities are normalized may have artificially low diagnosis rates, masking the true prevalence.
The Link to Infertility
PCOS is the single most common cause of ovulatory dysfunction. Up to 80% of women who aren’t ovulating regularly have PCOS as the underlying reason. Because ovulation is necessary for natural conception, this makes the condition a leading driver of infertility. That said, most women with PCOS can conceive with treatment or lifestyle changes. The condition doesn’t mean infertility is inevitable, but it does mean getting pregnant often takes longer or requires medical support.
Health Risks Beyond Fertility
The condition is closely tied to how the body processes insulin, which is why the CDC groups PCOS information alongside diabetes resources. Women with PCOS are significantly more likely to develop type 2 diabetes, gestational diabetes during pregnancy, and cardiovascular risk factors like high blood pressure and abnormal cholesterol levels. The metabolic effects of PCOS don’t end at menopause either. The elevated long-term risks for diabetes, stroke, and heart disease persist well beyond reproductive years.
The Financial Cost
Treating PCOS and its related complications cost an estimated $8 billion annually in the United States as of 2020, according to an analysis highlighted by the Endocrine Society. That figure breaks down into two major buckets. About $3.7 billion goes toward diagnosing and managing the reproductive symptoms, things like irregular periods, infertility treatment, and hormonal management. Another $4.3 billion covers the long-term metabolic consequences: diabetes care, stroke treatment, and cardiovascular management.
Pregnancy complications like gestational diabetes and preeclampsia account for about 5% of the total cost. The initial diagnostic process, despite often being a frustrating and drawn-out experience for patients, represents less than 2% of the overall economic burden. The real expense comes from years of managing the downstream health effects.
Why So Many Cases Go Undiagnosed
The 70% underdiagnosis rate exists for several overlapping reasons. Many women assume irregular periods are just how their body works, especially if they started that way in adolescence. Symptoms like weight gain, acne, and hair thinning are often treated individually by different specialists without anyone connecting them to a single hormonal condition. Some providers are also reluctant to diagnose PCOS in teenagers because the symptoms overlap so heavily with normal puberty, leading to a years-long delay before a diagnosis is made.
If you have persistently irregular cycles (fewer than eight periods a year, or cycles longer than 35 days), unexplained weight gain concentrated around the midsection, or signs of excess androgen like coarse facial hair growth, these are the patterns worth bringing up with a healthcare provider. A combination of blood work and ultrasound can typically confirm or rule out the diagnosis in a single visit.