Understanding PCOS: Symptoms, Diagnosis and What the Research Says
General health information. This article is not medical advice — please speak to your doctor about your own situation.
If you have been told your bloodwork is normal while your body clearly disagrees, you are in familiar company. Polycystic ovary syndrome is one of the most common endocrine conditions affecting women of reproductive age, and it is also one of the most frequently missed. Many people spend years collecting individual explanations — irregular cycles put down to stress, skin changes to hormones, weight changes to willpower — before anyone connects them.
This article covers what PCOS is, how it is diagnosed, and what current clinical guidance says about managing it.
The name is misleading
PCOS is not a disease of cysts. The follicles seen on an ultrasound in PCOS are not cysts at all — they are ordinary immature follicles, present in larger numbers than usual because ovulation is happening irregularly or not at all. Nothing is growing where it should not be.
It is better understood as a hormonal and metabolic syndrome. The clinical picture typically involves some combination of irregular ovulation, higher-than-usual androgen levels, and a particular ovarian appearance on imaging. Not everyone has all three, which is a large part of why it goes unrecognised.
Many women with PCOS have entirely normal-looking ovaries. Many have regular-seeming cycles. Some have neither weight changes nor visible skin symptoms. There is no single presentation.
How it is diagnosed
Diagnosis in most of Europe follows the Rotterdam criteria: at least two of the following three, once other conditions with similar presentations have been excluded.
Irregular or absent ovulation. Usually noticed as cycles that are consistently longer than 35 days, fewer than eight periods a year, or unpredictable timing.
Elevated androgens. Either measured on a blood test, or evident clinically — persistent adult acne, unwanted hair growth in a male pattern, or hair thinning at the scalp.
Polycystic ovarian morphology. A characteristic number of follicles or an increased ovarian volume on ultrasound.
The 2023 international evidence-based guideline updated this in two useful ways. Anti-MĂĽllerian hormone (AMH) can now be used in adults as an alternative to ultrasound, which spares many women a scan. And ultrasound is no longer recommended for diagnosis within eight years of a first period, because irregular cycles and multi-follicular ovaries are simply normal during that window.
Crucially, PCOS is a diagnosis of exclusion. Thyroid disease, elevated prolactin, and late-onset congenital adrenal hyperplasia can all produce a similar picture and are ruled out first.
Why it takes so long to get an answer
International surveys consistently find that a large proportion of women wait more than two years and see three or more clinicians before receiving a diagnosis. Several things drive that.
The symptoms present to different specialties. Skin changes go to a dermatologist, cycle irregularity to a gynaecologist, weight and metabolic concerns to a GP. Each is looking at one part of the picture.
Hormonal contraception can also mask it. The pill regulates withdrawal bleeds and often improves skin, so someone who started it as a teenager may only discover an underlying pattern years later when they stop.
And “normal” results can be genuinely misleading. Standard reference ranges are wide. A testosterone level at the upper end of normal, combined with cycles at the outer edge of normal, may still represent a meaningful pattern that no single test flags.
The metabolic side
A substantial proportion of women with PCOS have some degree of insulin resistance, and this appears to be present independently of body weight — lean women with PCOS can have it too.
This matters because it is linked to the longer-term health considerations associated with the condition, including cardiovascular and metabolic risk. It is one of the reasons clinical guidance recommends periodic screening rather than treating PCOS purely as a fertility or cosmetic issue.
Two other things are worth knowing. Sleep apnoea occurs more frequently in women with PCOS and is often missed. And when periods are absent for long stretches, clinicians will usually want to ensure the uterine lining is being shed periodically.
What management usually looks like
Care is directed at whichever symptoms matter most to the individual, so two people with the same diagnosis may be offered quite different things.
Lifestyle measures are first-line in every major guideline. The evidence supports regular physical activity and dietary patterns that are sustainable long-term. No single named diet has proven superior in trials.
Combined hormonal contraception is commonly used where cycle regularity, acne or unwanted hair growth are the priority.
Metformin may be considered where metabolic features are prominent.
Letrozole is first-line for ovulation induction in women trying to conceive, having outperformed clomiphene in trials for this population.
Which of these is appropriate depends entirely on individual circumstances, and all of them are decisions to make with a clinician.
PCOS and fertility
Irregular ovulation makes conception less predictable, not impossible. Many women with PCOS conceive without intervention, and many more do so with ovulation induction. The condition also does not affect egg quantity in the way some other causes of subfertility do — if anything, ovarian reserve markers tend to run higher.
The practical difficulty is often timing. When cycles are unpredictable, standard advice about ovulation windows becomes hard to apply, and tracking methods calibrated to a 28-day cycle can mislead.
If you have been trying for a year without success — or six months if you are over 35 — that is the point at which most European guidance suggests seeking assessment. With known cycle irregularity, it is reasonable to ask earlier.
Preparing for an appointment
A few things tend to make consultations more productive.
Bring cycle dates for as long a period as you can reconstruct, even roughly. Note when symptoms began rather than just that they exist. If you have had bloodwork done previously, bring the actual numbers rather than the summary — reference ranges vary between laboratories, and a value described as normal in one may read differently in another.
If you have felt dismissed before, it is entirely reasonable to ask directly whether PCOS has been considered and, if it has been excluded, on what basis.
The short version
PCOS is common, frequently under-recognised, and highly variable in how it presents. It is diagnosed by pattern rather than by a single test. Management is directed at the symptoms that matter most to you, and the evidence base has moved considerably in recent years.
If any of this sounds like your experience, it is worth a conversation with a doctor who will look at the whole picture rather than one part of it.
This article provides general information about a medical condition and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the guidance of a qualified healthcare provider with any questions you may have.
