If you’ve ever wondered why your periods are irregular, your skin suddenly breaks out, or losing weight feels like an uphill battle, PCOS might be part of the picture. Polycystic Ovary Syndrome (PCOS) affects around 1 in 10 women of reproductive age in the U.S., but despite being so common, it’s still widely misunderstood. Because symptoms vary — and not everyone experiences them in the same way — many women go undiagnosed for years. Let’s break down what PCOS really is, what causes it, the symptoms to look out for, and how doctors make a diagnosis.

What is PCOS?

Polycystic Ovary Syndrome (PCOS) is a hormonal imbalance that affects how the ovaries work. Women with PCOS often have higher levels of “male” hormones (androgens) and may not ovulate regularly. Despite the name, not everyone with PCOS has ovarian cysts — and having cysts doesn’t automatically mean you have PCOS.

What causes PCOS?

The exact cause isn’t fully understood, but several factors seem to play a role:

• Hormonal imbalance: Higher levels of androgens can disrupt ovulation.
  
  
• Insulin resistance: Many women with PCOS have trouble using insulin effectively, which can lead to weight gain and increase the risk of type 2 diabetes.
  
  
• Genetics: PCOS often runs in families, suggesting a hereditary link.

Common symptoms of PCOS

Symptoms vary widely, which is one reason diagnosis can take so long. Common signs include:

• Irregular or missed periods
  
  
• Difficulty getting pregnant (due to lack of ovulation)
  
  
• Excess hair growth on the face, chest, or back (hirsutism)
  
  
• Oily skin and acne
  
  
• Weight gain or difficulty losing weight
  
  
• Thinning hair on the scalp
  
  
• Darkened patches of skin (often on the neck, groin, or under the breasts)
  

Not everyone will experience all of these symptoms — some women only notice one or two.

How is PCOS diagnosed?

There’s no single test for PCOS. Doctors usually diagnose it based on a combination of medical history, symptoms, blood tests, and ultrasounds. The Rotterdam criteria are commonly used, meaning a PCOS diagnosis is likely if two of the following are present:

• Irregular or absent ovulation
  
  
• High androgen levels (measured in blood tests or shown through symptoms like excess hair)
  
  
• Polycystic ovaries on ultrasound

Because other conditions can mimic PCOS, ruling out thyroid problems or elevated prolactin levels is also part of the process.

The bottom line

PCOS is common, but it’s also complex. Symptoms can be frustrating, confusing, and sometimes dismissed. If you think you might have PCOS, speaking to a doctor is the first step toward answers and support.

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