PCOS is one diagnosis covering at least four fairly different presentations. Which is why advice that transformed someone else can do almost nothing for you, and why the internet argues about this condition endlessly without anyone being straightforwardly wrong.
Why there are four
The Rotterdam criteria diagnose PCOS when two of three features are present: irregular or absent ovulation, clinical or biochemical signs of high androgens, and polycystic ovaries on ultrasound.
Two out of three means several different combinations qualify. Two women with the same diagnosis may share almost no features.
The four presentations
Insulin-resistant. The most common by a distance. High fasting insulin, energy crashes, cravings, weight that resists effort, often dark velvety skin at the neck or underarms. Blood sugar work is the lever here and it moves everything downstream.
Post-pill. Cycles were regular on hormonal contraception, then stopped or went erratic after coming off. Androgens rebound as sex hormone binding globulin falls. Often temporary and frequently misread as permanent — see coming off the pill.
Inflammatory. Normal or near-normal insulin markers, but raised inflammatory markers, digestive symptoms, skin flares, fatigue and often headaches. Gut work and omega-3s matter more here than chasing an insulin problem you do not have.
Lean. A BMI in the normal range, which routinely delays diagnosis by years because clinicians are looking for a different body. Insulin resistance can still be present — it is simply not visible from the outside, which is exactly why fasting insulin should be tested rather than assumed.
One diagnosis, four starting lines. Get your labs before you pick a direction.
An honest caveat
These four categories are a clinically useful framework, not formal diagnostic subtypes with agreed criteria. Plenty of women sit across two of them. Treat this as a way to prioritise your first moves, not a label to identify with.
How the phenotype changes your first move
If you are insulin-resistant, meal sequencing and a post-meal walk will do more in eight weeks than any capsule.
If you are post-pill, patience plus androgen support matters more, and aggressive metabolic intervention may be solving a problem you do not have.
If you are inflammatory, chasing insulin markers that are already normal will frustrate you for months. Gut diversity and omega-3s are the better opening.
If you are lean, the risk is being told nothing is wrong. Insist on fasting insulin rather than fasting glucose alone.
What to test
The panel that distinguishes between these is listed, with wording that tends to work, in the lab request script. The key discriminators are fasting insulin, DHEA-S versus total testosterone, and an inflammatory marker such as CRP.
Questions people actually ask
Can my phenotype change over time?
Yes. Post-pill presentations often resolve. Insulin resistance can develop or improve. Retesting every year or two is reasonable rather than assuming your first labs are permanent.
What if I fit two categories?
Very common. Work the insulin lever first if it is present at all, because it influences androgens directly and improves the others indirectly.
Do I need an ultrasound?
Not always. Under Rotterdam you can be diagnosed on the other two criteria. Polycystic ovaries alone, without irregular cycles or high androgens, is not PCOS.
Is adrenal PCOS a real thing?
It is sometimes used to describe a presentation where DHEA-S is the dominant raised androgen. It is a useful shorthand rather than a formal category, and it points toward the stress work.
More in the hormone health section.