Why did so many women with PCOS go undiagnosed for years?

Up to 70 percent of women with PCOS went undiagnosed, according to the World Health Organization. That is not a small oversight. It is a systemic failure rooted in a name that sent patients and providers alike looking for something that was not actually there. The name polycystic ovary syndrome pointed everyone toward ovarian cysts, which most women with the condition do not have, while the real drivers, hormonal dysregulation, insulin resistance, and metabolic dysfunction, went unexamined. The rename to PMOS, polyendocrine metabolic ovarian syndrome, is a direct response to that failure.

The cyst problem: how a name created a diagnostic blind spot

When a condition is named after a structural feature, clinicians and patients reasonably expect that feature to be present at diagnosis. For PCOS, that expectation was consistently wrong. The structures described as cysts on ultrasound are actually arrested follicles, small, undeveloped egg sacs that did not mature and ovulate as they should. They are not pathological cysts in the clinical sense of the word.

According to the Lancet consensus paper published May 12, 2026, pathological ovarian cysts are not increased in the condition. Yet because the name implied they should be, women who presented without visible ovarian changes on ultrasound were frequently told they did not have PCOS, even when they had every other feature of the condition.

This created a diagnostic loop that researchers have described for years. A woman arrives with irregular cycles, acne, fatigue, excess hair growth, and difficulty maintaining stable weight. Her ultrasound does not show the expected cyst pattern. She is told she probably does not have PCOS and sent home without an explanation, without metabolic screening, and without support for the symptoms that are genuinely affecting her daily life.

"This name change isn't just semantics. It's science finally catching up to what women have been experiencing for years."

— Amy Suzanne Upchurch, Founder and CEO of Pink Stork

What was being missed while the focus was on ovaries

While the diagnostic conversation centered on ovarian appearance, the underlying metabolic and endocrine features of the condition were frequently overlooked. Insulin resistance is present in the majority of women with PMOS, including those who are not overweight. Elevated androgens affect skin, hair, and mood. Chronic low-grade inflammation contributes to fatigue and metabolic strain. Cardiovascular risk factors can begin accumulating years before a formal diagnosis is made.

The American Journal of Managed Care reported that the renaming reflects growing recognition that insulin resistance is common even in women who are not obese, and is linked to elevated risks of impaired glucose tolerance, dyslipidemia, hypertension, and cardiovascular disease. These are not fertility complications. They are metabolic health risks that develop over years and decades when the underlying condition goes unaddressed.

The mental health dimension was similarly underrecognized. As CNN reported in its coverage of the name change, researchers have increasingly associated the condition with sleep apnea, depression, anxiety, and body dysmorphia. These are not coincidental co-occurrences. They are part of the whole-body picture of a multisystem endocrine condition that medicine spent decades classifying as primarily a reproductive problem.

The diagnostic delay in numbers

The scale of missed diagnosis is significant. The World Health Organization estimates that up to 70 percent of women with the condition are undiagnosed. The condition is believed to affect between 10 and 13 percent of women of reproductive age worldwide, which means more than 170 million women globally, according to the Endocrine Society. Applied to those numbers, the undiagnosed majority represents tens of millions of women managing symptoms they cannot name, seeking explanations their providers cannot give them, and accumulating metabolic health risks that go unmonitored.

For individual women, the delay is not abstract. It translates to years of symptom management without understanding, fertility challenges that arrive without warning, and a persistent sense that something is wrong with them rather than that something has been missed by a system that was looking in the wrong place.

"We should believe women's pain. It takes about 8 to 9 years before women are diagnosed with endometriosis."

— Dr. Tosin Odunsi, MD, MPH, FACOG, Obstetrics and Gynecology Physician

How PMOS is designed to close the diagnostic gap

The name PMOS does not change the diagnostic criteria immediately. Women and providers will still use the same core clinical markers: irregular or absent ovulation, signs of excess androgens, and ultrasound findings where relevant. What the name changes is the frame those criteria sit within.

When the name points toward the endocrine and metabolic systems rather than the ovaries, providers are more likely to consider the condition in women who do not have a classic ultrasound presentation. They are more likely to run metabolic screening, including fasting insulin, glucose tolerance, and lipid panels, alongside reproductive assessments. They are more likely to refer to endocrinologists and metabolic specialists, not just gynecologists, when symptoms point to a multisystem condition.

Dr. Melanie Cree, MD, PhD, a pediatric endocrinologist at the University of Colorado Anschutz and one of the authors of the Lancet paper, said the previous name overlooked the condition's metabolic and hormonal complexity, leaving many patients undiagnosed or misunderstood, as reported by the University of Colorado Anschutz. The new name, she noted, helps shift the conversation toward overall health rather than a single aspect of the condition.

What this means if you were diagnosed, or not diagnosed, under the old name

If you received a PCOS diagnosis, that diagnosis remains valid. Your clinical picture has not changed. What may change over time is the type of care you are offered, with greater attention to metabolic screening, cardiovascular risk assessment, and the psychological dimensions of the condition.

If you were told you did not have PCOS because your ultrasound did not show cysts, or because your symptoms did not fit the expected profile, the PMOS renaming is particularly relevant for you. The condition does not require visible cysts for diagnosis. If you continue to experience irregular cycles, signs of elevated androgens, persistent metabolic symptoms, or any combination of these, a conversation with your healthcare provider about PMOS, specifically about metabolic and endocrine screening, is worth initiating.

"I assume that the change they're experiencing is menopause until proven otherwise, because they had a certain lifestyle and a certain feeling, and they know their body," says Dr. Tosin Odunsi, MD, MPH, FACOG. That principle applies here too. Women know their bodies. When something is wrong, that knowledge deserves clinical investigation, not dismissal.

For the broader context on what the PMOS name change means for diagnosis and treatment going forward, see our guide on how the name change will affect diagnosis and treatment. For an explanation of why PMOS is classified as a metabolic condition, see what PMOS and insulin resistance have to do with each other.

Frequently asked questions

Why were so many women with PCOS undiagnosed?

The name PCOS implied that ovarian cysts were the defining feature of the condition. Many women with the condition do not have visible cysts on ultrasound, and when they presented without this expected finding, they were often dismissed or delayed. The metabolic and endocrine drivers of the condition were frequently overlooked because the name directed attention elsewhere.

Does PMOS require ovarian cysts for diagnosis?

No. The diagnostic criteria for PMOS, like those for PCOS, do not require ovarian cysts. The core criteria are irregular or absent ovulation, signs of excess androgens such as acne, excess body or facial hair, or hair thinning, and relevant ultrasound findings. Not all criteria need to be present simultaneously. You can speak with your healthcare provider about which criteria apply to your situation.

What symptoms are associated with PMOS that are often missed?

Beyond cycle irregularity and visible androgen effects like acne and excess hair, PMOS is associated with insulin resistance, fatigue, difficulty maintaining stable weight, mood changes, sleep disruption, and, in some research, increased risk of anxiety, depression, and sleep apnea. These symptoms are frequently attributed to unrelated causes rather than recognized as part of a multisystem endocrine condition.

If I was told I did not have PCOS, should I be retested for PMOS?

If your previous evaluation focused primarily on ovarian ultrasound and you continue to experience symptoms that could be consistent with PMOS, a conversation with your healthcare provider about updated evaluation, including metabolic and endocrine screening, is worth having. Bring a written record of your symptoms, including energy, mood, skin, cycle, and weight history.

How long does it typically take to get a PMOS diagnosis?

Under the old PCOS framework, diagnostic delays of several years were common. The hope of the PMOS renaming is that a name pointing toward metabolic and endocrine features will prompt earlier and broader investigation, reducing the time between symptom onset and diagnosis. The transition will take time as clinical guidelines and provider education are updated.

What is the first step if I think I might have PMOS?

The first step is a conversation with your healthcare provider. Come prepared with a written record of your symptoms across all relevant systems: cycle regularity, energy, skin, hair changes, mood, sleep, and weight. Ask specifically about metabolic and endocrine screening alongside any reproductive evaluation. If your provider is unfamiliar with the PMOS name, note that it was published in The Lancet in May 2026 as the renamed version of PCOS.

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