How PCOS Is Diagnosed: Ultrasound, Hormones, and Symptoms

ByTarin Hussain
Updated: 1 Jan 2026, 3:30 pm
Medically Reviewed by Dr. N Sapna Lulla,

If you have been having irregular periods, extra hair growth, stubborn acne, or difficulty getting pregnant, your doctor might suspect polycystic ovary syndrome (PCOS). It is one of the most common hormone problems in women of reproductive age.

Pregatips
Polycystic ovary syndrome (PCOS) isn’t always obvious, and that’s exactly why understanding how PCOS is diagnosed is so important. You might notice irregular cycles, stubborn acne, or sudden weight changes. But none of these signs alone can confirm what’s really going on inside your body. PCOS shows up differently for every person, which is why doctors don’t rely on just one clue. They look at a combination of symptoms, blood tests, and imaging to understand the full picture.
In this article:

A proper diagnosis is important for choosing the right treatment and taking control of your health.


How PCOS Is Diagnosed


PCOS does not have one straightforward blood test or scan that says “yes” or “no”. Instead, doctors use a set of internationally accepted guidelines called the Rotterdam criteria. To confirm PCOS, you need at least two out of these three main markers, and other similar conditions must first be ruled out:

  • Irregular or absent periods (fewer than eight periods a year or cycles longer than 35 to 40 days)
  • Signs of high male hormones (androgens), either from blood tests or physical signs like excess facial/body hair, severe acne, or hair thinning on the scalp
  • Polycystic appearance of ovaries on ultrasound (many small follicles)
PCOS is officially diagnosed only when at least two of these are present.


What PCOS Symptoms Do Doctors Look For?


Your doctor will start by talking to you in detail. They will ask:

  • How regular your periods are, and when you last had one.
  • Whether you have noticed extra hair on the face, chest, or abdomen.
  • If acne has been difficult to control even after the teenage years.
  • Any recent weight gain that feels hard to shift.
  • If you are trying to conceive and facing delays.
  • Family history, because PCOS often runs in families.
They will also do a physical check for excess hair, acne, skin tags, darkened skin patches (especially in neck folds or underarms), and sometimes measure your blood pressure and weight.


Which Blood Tests Are Done To Diagnose PCOS?


Blood tests play a big role in confirming high androgen levels and ruling out other causes. Common tests include:

  • Total testosterone and free testosterone: It is often raised in 60 to 80 per cent of people with PCOS.
  • Sex hormone binding globulin (SHBG): This is usually low, which allows more testosterone to stay active in the body.
  • Dehydroepiandrosterone sulphate (DHEAS): This may also be checked, especially if androgen levels seem unusually high.
  • Fasting glucose, insulin levels, and a glucose tolerance test: These help check for insulin resistance, which is very common in PCOS.
  • Cholesterol and triglyceride levels: These are measured because PCOS can increase the risk of heart problems later in life.
  • Thyroid function tests and prolactin levels: These are done to ensure irregular periods are not due to thyroid disorders or other hormone issues.
If these tests show high male hormones or insulin resistance along with irregular cycles, it gives a much clearer picture and strongly points toward PCOS.


How Does Ultrasound Help in PCOS Diagnosis?


Ultrasound is the imaging test doctors rely on to see the ovaries clearly. In most cases, a transvaginal ultrasound (where a small probe is placed inside the vagina) gives the best pictures, especially if you carry extra weight around the tummy. It is safe, takes only a few minutes, and usually causes just mild discomfort.

What the scan looks for:

  • Many small follicles (immature egg sacs), usually 12 or more follicles that are 2 to 9 mm in size in at least one ovary.
  • Or an increased ovarian volume of more than 10 cubic centimetres.
Only one ovary meeting these criteria is enough.

However, these are some important points you should remember:

  • These small follicles are not harmful cysts. They are just resting eggs that did not mature and release because of the hormone imbalance.
  • You can have PCOS even if the ovaries look completely normal on scan.
  • Similarly, many people have polycystic-looking ovaries on scan but never develop symptoms of PCOS.
If you have never been sexually active or prefer not to have a transvaginal scan, a transabdominal scan (done over the tummy with a full bladder) can be arranged, though the pictures may not be as sharp.


Is the Anti-Müllerian Hormone (AMH) Test Useful For PCOS Diagnosis?


A blood test for anti-Müllerian hormone (AMH) can sometimes be used instead of an ultrasound because people with PCOS usually have higher AMH levels. However, it is not yet part of the official diagnostic criteria everywhere, so most doctors still prefer the traditional combination of symptoms, blood tests, and ultrasound.


What Other Conditions Need to Be Ruled Out Before Diagnosing PCOS?


Several other health issues can mimic PCOS, so your doctor will make sure these are not the real cause:

  • Thyroid disorders (both low and high thyroid function)
  • High prolactin levels (hyperprolactinaemia)
  • Congenital adrenal hyperplasia (a rare genetic condition)
  • Cushing’s syndrome
  • Androgen-producing tumours (very rare)
Only after these are excluded can the diagnosis of PCOS be confidently made.

If you recognise several of these signs in yourself, do not worry. Book an appointment and talk openly with your doctor. PCOS is very common, very manageable, and getting a clear diagnosis is the first step towards feeling better and protecting your future health. You are definitely not alone in this!

You’re not alone in your journey when trying to conceive. Join our supportive community to connect with others, share experiences, and find encouragement every step of the way.

FAQs on How PCOS Is Diagnosed: Ultrasound, Hormones, and Symptoms

  1. How to manage pregnancy if I have PCOS?
    Pregnancy with PCOS is usually safe with proper monitoring, but you may need closer checks for blood sugar, blood pressure, and foetal growth.
  2. Does having regular periods rule out PCOS?
    No, regular cycles do not rule out PCOS. Some people maintain normal-looking periods but still have high androgens or polycystic ovaries.

Related Stories

  1. Understanding What a PCOS Ultrasound Shows
  2. How PCOS Is Diagnosed: Ultrasound, Hormones, and Symptoms
  3. Ayurvedic Approach to Fertility: Understanding Beej, Kshetra, Ambu, and Ritu Before Conception
  4. Hormonal Acne and Fertility: The Connection You Did Not Know
  5. Can Minimalism Reduce Fertility Stress
  6. Secondary Infertility in India: Understanding IVF After the First Baby
How we reviewed this article
Our team continuously monitors the health and wellness space to create relevant content for you. Every article is reviewed by medical experts to ensure accuracy.