Dr. Mélanie DesChâtelets, ND

By Dr. Mélanie DesChâtelets, ND. Licensed naturopathic doctor and founder of PMOS Health Collective.

If you were diagnosed with PCOS as a teen, there’s something worth knowing: the rules used to diagnose PMOS (formerly PCOS) before age 20 are different from the adult ones, and stricter. A teenage body is still finding its rhythm, so some features that look like PCOS at 15 are just a normal phase. That’s why a label given years ago is worth a second look now, not to second-guess your care, but to make sure you’d actually have met the adolescent criteria in the first place. Here’s how to check.

One quick convention before we start: I’ll use age 20 as the line between the teen rules and the adult rules, just to keep it simple. The real line is about 8 years after your first period. For most of you that lands around 20, for some a little sooner or a little later. So whenever you see 20 in here, read it as shorthand for that 8-year mark.

And one quick note. This is education, not medical advice, and I’m not your naturopathic doctor. Read it, take notes, then bring your history to your own care team.

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Why teen diagnosis works differently

In the years right after a first period, the communication between the brain and the ovaries is just getting started. So some things that look like PCOS in a teenager are actually normal for the stage. That’s also why PCOS can look so different from one person to the next, and why a teen label given years ago deserves a recheck. To avoid over-diagnosing during a normal phase, the criteria are stricter before age 20. If you were diagnosed back then, the first thing to know is that the bar was supposed to be higher, not lower.

The adolescent rule: two of two, not two of three

Before age 20, there’s no reliable way to assess ovarian morphology, so ultrasound and AMH are off the table. That turns the adult “two out of three” rule into a stricter “two out of two.” You need both: irregular cycles (defined specifically for teens, below) and androgen signs, either symptoms or bloodwork. If only one of the two was present, that isn’t a full diagnosis. It can be considered “PCOS at risk,” but only once other causes for the symptoms have been explored first. So when you look back at your file, the question is: did I clearly have both?

Reading the androgen box as a teen

The visible signs come first: aggressive acne that doesn’t respond well to treatment or persists as you get older, hair thinning where the part keeps widening, or excess hair on the face tracking toward the belly button or down the legs.

Here’s a clinical pearl worth carrying, especially in hindsight: in PCOS, high-androgen symptoms tend to come on slowly and progressively. If excess facial hair showed up very suddenly and very severely, that can point to other causes and deserves a different workup. So if your symptoms came on fast back then, that’s worth raising clearly with your provider now, so the right testing gets done.

The cycle definitions change by year

This is the part defined differently than for adults, and it hinges on how many years it had been since your first period. In the first year, irregular cycles are normal. From one to under three years out, cycles shorter than 21 days or longer than 45 days count as irregular. At three years and beyond, the window tightens to shorter than 21 or longer than 35. And at any point more than a year out, a single cycle of 90 days or more counts. So “my cycles were irregular as a teen” only means something against the right year-based window. Worth checking which window you were actually in.

Why a teen ultrasound doesn’t count

You may have had a pelvic ultrasound back then for any number of reasons, but for diagnosing PCOS it isn’t reliable until it’s been about 8 years since your first period (which for many lands around age 20). Before that, the ovaries normally show more follicles, so the scan can look “polycystic” when nothing is wrong. So if your teen diagnosis was hanging mostly on an ultrasound, that’s the single biggest reason to revisit it and check whether the other two criteria were actually met.

“PCOS at risk,” and when to reassess

Some teens have a few features but not quite enough for a clear diagnosis: maybe some irregular cycles but little on the androgen side, or the reverse. Once other causes are ruled out, that’s “PCOS at risk.” Not a no, not a yes, a “let’s keep an eye on this.” The recommendation is to reassess once it’s been at least 8 years since the first period (around age 20 for many), when ovarian morphology testing finally becomes accurate, either by ultrasound or by AMH if you’d rather skip an internal scan.

So if you’re carrying a teen label into adulthood, the empowering move is simple: pull your records, see whether you met two of two, and bring it to your provider as a clear question. “I was diagnosed as a teen. Looking at the adolescent criteria, can we confirm I still meet a PCOS diagnosis now?” Whether the answer is a yes, a not-yet, or a watch, knowing exactly where you stand is the whole point, because every decision after it depends on getting this part right.

Watch the full video: Is This Really PCOS? Teen Edition, and subscribe to my YouTube channel.

This article is educational, not medical advice or a diagnosis. If something here resonates, bring it to your healthcare team, who can look at it through the lens of your individual health.

By Dr. Mélanie DesChâtelets, ND. Licensed naturopathic doctor and founder of PMOS Health Collective.

Were you ever actually diagnosed with PMOS (formerly PCOS), or was the label just handed to you? It’s one of the most common things I hear: some people are sure they have it but no one ever confirmed it, and others were told they have it but it doesn’t sit right. This is a plain-English walk through the PCOS diagnosis criteria for adults, so you can pull up your own records and see how they line up. The goal isn’t to diagnose yourself. It’s to walk into your next appointment knowing exactly what the criteria are, and asking sharper questions.

One quick convention before we start: I’ll use age 20 as the cutoff throughout, just to keep it simple. The real line is about 8 years after your first period. For most of you that lands around 20, for some a little sooner or a little later. So whenever you see 20 in here, read it as shorthand for that 8-year mark.

And one quick note. This is education, not medical advice, and I’m not your naturopathic doctor. Think of it as a translation guide. Read it, take notes, then bring your actual history and results to your own care team.

▶ Liked this video? Subscribe on YouTube.

What are the adult PCOS diagnosis criteria?

For adults, the PCOS diagnosis criteria come down to what’s called the Rotterdam rule, or the “two out of three.” You meet it when two of these three are present, after other causes have been ruled out: signs of high androgens, irregular cycles, or polycystic ovarian morphology (seen on ultrasound, or as an elevated AMH on bloodwork). Two of three. Not one.

One nuance on the age line, because it matters when you read your own history: what counts isn’t your birthday, it’s that it’s been about 8 years since your first period (which for most people lands around age 20). Before that, the rules are different and stricter. The “ruling out other causes” half is its own important step (and its own article). For now, picture the inclusion side as three boxes, and you’re checking how many you actually tick.

How do you read the “high androgens” box?

This box can be ticked two ways: by symptoms or by labs. The symptoms look like excess hair growth on the face or tracking toward the belly button and thighs, persistent acne that doesn’t ease after the teen years (or that’s more aggressive and treatment-resistant when younger), or female-pattern hair thinning at the crown where the part slowly widens.

Here’s the part worth knowing as you read your file: if those symptoms are clearly present, that alone can count. Bloodwork isn’t always required to tick this box, because the signs are visible. When symptoms are subtle, that’s when labs help, and the names to look for are total and free testosterone, the free androgen index (a calculation used when free testosterone isn’t measured directly), and sometimes DHEA-S. So if your chart shows clear androgen symptoms, the box can be ticked without a lab number, which surprises a lot of people scanning their own records for a “positive test.”

Why a pill-era androgen result doesn’t count

A major pearl when you’re checking dates against results. If you were on the combined oral contraceptive pill when your androgens were measured, those numbers aren’t reliable. The pill raises sex hormone binding globulin and lowers your available androgens, so a normal-looking result on the pill doesn’t tell you much. If testing is genuinely needed, the guideline approach is to come off the pill for at least three months, use another form of contraception in the meantime, and then test. So a question worth bringing to your appointment: “was I on the pill when my androgens were tested?”

What actually counts as an irregular cycle?

This one is defined more specifically than most people expect. It isn’t being off by a couple of days. Irregular means cycles shorter than 21 days or longer than 35 days, or fewer than eight cycles a year. And if you’re more than a year past your first period and you’ve had a single cycle stretch past 90 days, that counts too. Worth comparing against whatever cycle history you’ve tracked, because “irregular” has an actual definition, not a vibe.

The ultrasound box, and the 2023 AMH option

This box collects the most myths, so here’s what to know when an ultrasound report shows up in your file. You don’t automatically need a pelvic ultrasound: if you already tick two of the three boxes, it isn’t required. An ultrasound done as a teenager doesn’t count for diagnosis, because a pelvic ultrasound isn’t reliable for PCOS until it’s been about 8 years since your first period (before that, the ovaries normally show more follicles and can look “polycystic” when nothing is wrong). And “polycystic ovarian morphology” does not mean ovarian cysts. What’s actually being counted is follicles. In plain language, how many eggs are in the running. Different thing entirely.

The 2023 update worth knowing: there’s now a blood test, AMH, that can stand in for the ultrasound. If AMH is elevated, it correlates with a high follicle count. That matters for access, because not everyone can get a pelvic ultrasound, and not everyone is comfortable with an internal one. So if you see an AMH on your panel, it may be doing the job the ultrasound would.

How to audit your own diagnosis

Here’s the empowering part, and it’s the whole reason to learn the criteria. You can pull up your own records and count: do I clearly tick two of the three boxes, with the age line and the pill timing accounted for? An irregular cycle on its own isn’t PCOS. Androgen symptoms on their own aren’t PCOS. One ultrasound line on its own isn’t PCOS. You need two of three, plus the other causes ruled out.

This isn’t about diagnosing yourself from a blog. It’s about walking in with a precise question instead of a vague worry: “Looking at the criteria, here’s what I think I do and don’t meet. Can we go through it together?” That’s the question that gets you a real answer. Because with clarity comes power, and when you understand what a PCOS diagnosis actually rests on, every decision after it gets easier.

Watch the full video: Do I Really Have PCOS or Not?, and subscribe to my YouTube channel.

This article is educational, not medical advice or a diagnosis. If something here resonates, bring it to your healthcare team, who can look at it through the lens of your individual health.