What PCOS is

Polycystic ovary syndrome is a set of symptoms related to a hormonal imbalance. That is the public description from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, usually called NICHD. This page stays inside what that description, and a 2023 international guideline summary, actually say.

The three features NICHD names

NICHD says women with PCOS usually have at least two of three features.

Absence of ovulation. NICHD describes ovulation as the ovary releasing a mature egg, usually monthly, and ties its absence to irregular menstrual periods or no periods at all.

High levels of hormones called androgens, or signs of high androgens. One sign NICHD names is increased body or facial hair.

Growths in one or both ovaries. NICHD describes these as often clumps of ovarian follicles that have stopped developing.

Some women diagnosed with PCOS have the first two features, and symptoms of PCOS, but do not have growths in their ovaries. A missing feature is not something this page can interpret for you. Assessment belongs with a clinician.

Symptoms that can seem unrelated

NICHD says women with PCOS may experience a range of symptoms that may seem unrelated to ovaries. The examples it gives are increased hair growth, dark patches of skin, acne, insulin resistance, and irregular menstrual bleeding. They are possible symptoms. The list is not a statement that every person has each one.

NICHD also says PCOS is the most common cause of anovulatory infertility, meaning infertility that results from the absence of ovulation, and that many women don't find out that they have PCOS until they have trouble getting pregnant. That is a description of how some people arrive at a diagnosis. It is not a prediction about any one reader.

Why the definition is still being argued over

The 2023 international evidence-based guideline summary says the earlier guideline moved from consensus-based to evidence-based diagnostic criteria. It also says the 2018 guideline was based on best available, but generally very low to low quality, evidence. The summary is frank about the consequences: diagnosis is still delayed, the needs of those with PCOS are not being adequately met, and evidence-practice gaps persist.

The same summary says the 2023 update includes 254 recommendations and practice points, and that women with PCOS were directly involved. A page like this one is not a substitute for the full guideline. The authors say the summary should be read with the full document.

NICHD adds that more recent genetic research suggests there may be two or more subtypes of PCOS. That is a suggestion from the research NICHD is pointing to, not a sorting tool you can apply to yourself from an article.

What a definition can and cannot do

A definition can help you recognize the words a clinician is using. It cannot tell you whether those words fit your body. Questions you might take to a visit include which features are being weighed, which symptoms are worth writing down, and what would change the assessment.

If you want a place to keep those observations, How to keep a PCOS symptom record is about the notes themselves. Why PCOS symptoms vary is about why one person's list can look unlike another's.

Alula can hold symptom and routine notes, including on a digital twin of what you log. It does not diagnose PCOS.

Where this leaves the evidence

The public definition is short. The guideline process behind assessment and care is large, and the people who wrote the 2023 summary say much of the underlying evidence has been low quality. Hold both of those facts at once. Use them to prepare a better conversation, not to close one.