PCOS Symptoms: What to Look For and How It’s Diagnosed

Last updated September 30, 2026. Educational information, not medical advice: see our Medical Disclaimer.

PCOS symptoms often show up as a cluster of unrelated-seeming changes: irregular periods, new acne in your late 20s, hair growth in new places. Each one is easy to dismiss on its own, but together they can point to one underlying condition. The U.S. Office on Women’s Health estimates PCOS affects about 1 in 10 women of childbearing age. The World Health Organization says up to 70% of women with PCOS remain undiagnosed, which makes it one of the most common, and most missed, hormonal conditions there is.

This guide covers what the symptoms actually look like and how PCOS is diagnosed under the current 2023 international guideline. It also covers how PCOS differs from perimenopause, and something most guides published before mid-2026 don’t mention: PCOS has a new name. If you’re also tracking perimenopause symptoms, see our perimenopause symptoms checklist for a related but separate picture.

In this article:

• What Is PCOS?
• PCOS Has a New Name: PMOS
• The PCOS Symptoms Checklist
• How Common Is PCOS?
• How PCOS Is Diagnosed
• PCOS or Perimenopause?
• Long-Term Health Risks
• When to See a Doctor
• PCOS Symptoms FAQ
• Your Next Step

What Is PCOS?

PCOS (polycystic ovary syndrome) is a common hormonal condition that affects ovulation, hormone levels and metabolism. Despite the name, it isn’t really about ovarian cysts. Professor Helena Teede, who led the international effort to rename the condition, has said there’s no actual increase in abnormal cysts on the ovary in PCOS, and that the old name undersold how much the condition affects the whole body, not just the reproductive system (Endocrine Society).

In practice, PCOS shows up differently from woman to woman. Some women notice period changes first, others notice skin or hair changes, others are diagnosed only when they have trouble conceiving. That variability is part of why PCOS is frequently missed or diagnosed late.

PCOS Has a New Name: PMOS

If you’ve read about PCOS before, you may not have seen this yet. On May 12, 2026, a paper in The Lancet announced the end of a 14-year global consensus process. PCOS is now officially named polyendocrine metabolic ovarian syndrome (PMOS) (Endocrine Society; University of Rochester Medicine). More than 50 patient and professional organizations took part, including the Endocrine Society.

A few things worth knowing:

• The diagnostic criteria did not change. Doctors are still assessing the same combination of symptoms: irregular periods, signs of elevated androgens, and ovarian changes on ultrasound (University of Rochester Medicine).
• Both names are in use right now. There’s a 3-year transition period, with full implementation targeted for the 2028 International Guideline update. If you’re already being treated for PCOS, keep following your provider’s current plan.
• The reason for the change: the old name focused on ovarian cysts, which aren’t actually a core feature of the condition, and left out its hormonal, metabolic, dermatological and psychological effects.

We use “PCOS” through most of this guide since that’s still the term most people search for and most current medical pages use, but you may start seeing “PMOS” more often as the transition continues.

The PCOS Symptoms Checklist

No one symptom on its own means you have PCOS. What matters is the pattern. Check what you’ve noticed over the past several months, then bring the list to a doctor rather than trying to self-diagnose from it.

Period Changes

• ☐ Periods fewer than 8 times a year
• ☐ Periods more than 35 days apart
• ☐ Absent periods
• ☐ Unpredictable or heavy periods

Androgen-Related Changes

• ☐ Excess hair growth on the face, chest, abdomen or upper thighs (hirsutism)
• ☐ Acne that started or worsened in your 20s or later, or doesn’t respond to usual treatments
• ☐ Thinning hair on the scalp

Weight and Metabolism

• ☐ Weight gain, or weight that’s hard to lose
• ☐ Skin that darkens or thickens in body folds (neck, armpits)
• ☐ Intense sugar or carbohydrate cravings

Fertility and Reproductive Health

• ☐ Trouble getting pregnant
• ☐ A history of miscarriage

Mood and Sleep

• ☐ Anxiety or low mood
• ☐ Trouble sleeping or a diagnosed sleep disorder

Hirsutism affects more than 7 in 10 women with PCOS, making it one of the more common androgen-related signs (ACOG).

How to read this list: period changes plus any androgen-related sign are the two features doctors weigh most heavily. If you’ve checked items in both of those groups, that’s a reasonable prompt to bring it up at your next appointment, though only a clinician can diagnose PCOS.

How Common Is PCOS?

Estimates vary depending on which diagnostic criteria and population a study uses, so we’ve included a range rather than one number:

The lowest figure comes from a 2024 US survey of 75,013 women (the National Health and Wellness Survey), which found a 6% lifetime diagnosis rate, about 3.5 million women aged 18 to 44, presented as a poster at ISPOR 2026. Since that figure counts only diagnosed cases, and the WHO estimates up to 70% of PCOS goes undiagnosed, the true prevalence is likely closer to the higher end of this range. The CDC separately estimates PCOS affects as many as 5 million women in the US.

Part of the spread comes down to methodology: studies using stricter diagnostic criteria, or relying only on existing medical records rather than screening, tend to report lower numbers, and PCOS is widely considered underdiagnosed regardless of which estimate you use.

How PCOS Is Diagnosed

There’s no single test for PCOS. Doctors diagnose it under the 2023 International Evidence-based Guideline, which built on the earlier Rotterdam criteria. You need at least 2 of these 3 features, after ruling out other conditions that cause similar symptoms:

1. Irregular or absent ovulation — reflected in irregular, infrequent or absent periods
2. Clinical or biochemical signs of high androgens — hirsutism, persistent acne, or elevated androgen levels on a blood test
3. Polycystic ovaries on ultrasound, or, as of the 2023 update, an elevated AMH (anti-Müllerian hormone) blood test can be used instead of ultrasound (2023 International Evidence-based Guideline, via ASRM)

If you already have both irregular cycles and signs of high androgens, that’s considered enough on its own, and ultrasound or AMH testing usually isn’t needed. For adolescents, the guideline is stricter. Both irregular ovulation and hyperandrogenism are required. Ultrasound or AMH aren’t recommended for teens, since ovarian appearance varies more in that age group and isn’t a reliable marker.

Because several other conditions, including thyroid disorders, can cause similar symptoms, your doctor will typically also rule those out before confirming a PCOS diagnosis.

PCOS or Perimenopause?

PCOS and perimenopause can look similar on the surface. Both involve irregular periods, weight changes, mood shifts and fatigue. But they’re different conditions with different timing.

PCOS symptoms typically begin around puberty, often years before perimenopause starts. Perimenopause, by contrast, usually begins in your 40s. The clearest signs pointing toward PCOS rather than perimenopause are the androgen-related features: hirsutism, persistent acne or scalp hair thinning, along with a history of irregular ovulation or fertility difficulty that predates your 40s.

There’s also a genuine, research-backed connection between the two: one recent population-based study found that women with PCOS tend to reach late perimenopause later, and report fewer menopausal symptoms at age 46, than women without PCOS (Lavi et al., Acta Obstetricia et Gynecologica Scandinavica, 2026). If you’re in your late 30s or 40s and unsure which is going on, a doctor can order targeted hormone and metabolic testing rather than relying on symptoms alone. If perimenopause turns out to be the better fit, our perimenopause vs menopause guide is a good next stop.

Long-Term Health Risks

PCOS is often framed around fertility, but it affects more than reproductive health, which is one reason getting a diagnosis matters even if you’re not trying to conceive right now.

• Type 2 diabetes and heart disease. Insulin resistance, common in PCOS, raises the risk of both. More than half of women with PCOS develop type 2 diabetes by age 40 (CDC; ACOG).
• Endometrial cancer. Irregular ovulation means fewer periods with less progesterone. That leaves the uterine lining with more chronic estrogen exposure, which stimulates it and can cause it to build up unusually thick (endometrial hyperplasia). Women with PCOS have about 2 to 3 times the risk of developing endometrial cancer compared with women without it (American Cancer Society, reviewed by ASCO).
• Infertility. Irregular or absent ovulation is a common cause of difficulty conceiving.
• Sleep apnea and depression. Both are more common with PCOS (ACOG).
• Metabolic syndrome. A cluster of conditions, including high blood pressure and abnormal cholesterol, that raises diabetes and heart disease risk together.

When to See a Doctor

Consider booking an appointment if:

• Your periods come fewer than 8 times a year, or more than 35 days apart
• You have new or worsening acne, hair growth or hair thinning alongside period changes
• You’ve been trying to conceive for 12 months (or 6 months if you’re 35 or older) without success
• Weight changes feel out of proportion to your diet and activity, especially alongside irregular periods
• You have symptoms that could point to diabetes or prediabetes, such as excessive thirst or fatigue, alongside other PCOS symptoms

A diagnosis usually starts with your period history and a physical exam, followed by blood tests and sometimes an ultrasound, so tracking your cycle for a few months before your appointment makes the visit more productive.

PCOS Symptoms FAQ

Your Next Step

If several of the items on the checklist above sound familiar, that’s worth a conversation with a doctor, not a self-diagnosis. Track your cycle for a few months, note which symptoms you’re noticing, and bring that record to your appointment. For related reading, see our guides on hormonal imbalance symptoms and perimenopause vs menopause.

About the author: Jessica Bordo writes Daily Health Cycle out of personal interest in women’s health, not as a clinician. She summarizes what sources such as ACOG, the CDC, WHO and the Endocrine Society say and links to them so you can check the claims yourself. No medical reviewer is listed for this article, so use it to prepare questions for your own clinician, not to replace their advice. Our authors page explains how we source and check articles.

This article is for general education and isn’t medical advice. See our full disclaimer and talk with a qualified clinician about your own care.

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