top of page

How is PCOS diagnosed?

Updated: Mar 25, 2022

how is pcos diagnosed with question mark and clipboard

Unfortunately, polycystic ovary syndrome, often referred to simply as PCOS, is widely underdiagnosed. I remember when I asked my OBGYN if she would test me for it, she brushed me off and said “if you grow a beard, give me a call”. I’m not joking- this really happened! I ended up seeing a reproductive endocrinologist (AKA fertility specialist) and he was able to diagnose me after an appointment in his office and receiving my bloodwork. My situation is not uncommon, as women generally need to meet with multiple providers before getting a PCOS diagnosis.

Equally unfortunate, being misdiagnosed seems to be common as well. There are many women who are told they have PCOS simply because they are overweight and unable to get pregnant. These are NOT diagnostic criteria!!

So how is PCOS actually diagnosed? To make things confusing (you’ll learn that nothing about PCOS is straightforward!), there used to be multiple ways it could be diagnosed. However, in 2012 at a National Institute of Health workshop, it was decided that only the Rotterdam criteria should be used moving forward.

According to the Rotterdam criteria, 2 out of the 3 criteria must be met for a diagnosis of PCOS (prepare for lots of medical jargon here- don't worry, we'll sort it out):

  • Oligomenorrhea or anovulation

  • Clinical and/or biochemical signs of hyperandrogenism

  • Polycystic ovaries

Oligomenorrhea or Anovulation

Oligomenorrhea - infrequent menstrual periods

Anovulation - when the ovaries do not release an egg

Irregular or long menstrual cycles is one of the criteria for diagnosis. Specifically, cycles greater than 35 days long would meet this criteria, or having 8 or less periods in a year. When tracking your menstrual cycles, the first day of your period is considered day 1.


Hyperandrogenism - an excess of male hormones

High male sex hormones, specifically testosterone, seems to be the classic sign of PCOS that people are most familiar with. Meeting this criteria can be done one of two ways:

1) Clinical signs - meaning observed symptoms suggestive of elevated male hormones. This can come in the form of hirsutism, acne or male pattern baldness. Hirsutism, a fancy word for male pattern hair growth, is common in PCOS. This hair growth may be found on the face, stomach, lower back, chest and other areas. Excessive acne is also considered a sign of hyperandrogenism. Male pattern baldness is not as common as the other clinical symptoms, but does present in some women.

2) Biochemical signs - meaning elevated male hormones via bloodwork. Elevated levels of total testosterone, free testosterone and/or DHEAS would be considered hyperandrogenism. If your doctor had you do bloodwork to look for PCOS, they most likely checked all three of these levels.

To clarify, clinical signs AND/OR biochemical signs of elevated male hormones need to be present to meet this criteria. So, you don't need to have both elevated lab values and clinical symptoms, you could just have one or the other.

Polycystic Ovaries

Having many immature follicles, also known as cysts, in the ovaries is the final criteria for the PCOS diagnosis. To find this out, a transvaginal ultrasound is performed. If one ovary has 12 or more follicles or the ovary is bigger than 10 cm, this would meet the criteria.

If you are having this test performed, the healthcare professional performing the ultrasound may show you the screen so you can see what they’re looking at. If you have polycystic ovaries, you will see many black circles on the screen, which some says look like a string of pearls.

These follicular cysts do not cause pain, so you wouldn't know if you had them or not on your own. The only way polycystic ovaries can be discovered is by ultrasound.

“Diagnosis of Exclusion”

PCOS is considered a “diagnosis of exclusion” meaning that other things should be ruled out before giving the diagnosis. Diseases such as cushing syndrome or an androgen-secreting tumor have many of the same features as PCOS.

Note About Birth Control

You cannot be on oral contraceptives while being evaluated for PCOS. Birth control pills force the body to have “periods” every 28 days, so menstrual cycles will appear normal. Birth control pills will also change the values of male sex hormones in the body. It is recommended to be off oral contraceptives for 3 months before testing for PCOS.

Putting it All Together

Again, meeting 2 out of the 3 criteria is needed for a PCOS diagnosis. It can be argued that some of these things are somewhat subjective, so that can add to the confusion. What one person considers “excessive acne” might be considered normal by another person. Your doctor may use some clinical judgement (their best guess based on their experience), while still being as objective as possible.

I’ve seen things like “your doctor can’t diagnosis you PCOS unless they do bloodwork” thrown around quite a bit on the internet. There’s also a picture on Pinterest with a woman holding a sign that says “PCOS cannot be diagnosed by ultrasound”. I do agree that a full assessment should be completed before suspected PCOS turns into an actual diagnosis. However, for some women, simply just talking about symptoms could provide enough information to meet 2 of the criteria. For example, if a woman says “My menstrual cycles last anywhere from 40-60 days” and “I had laser hair removal done on my face a few years ago” this would be enough for her doctor to diagnose her with PCOS.

What Criteria is NOT diagnostic of PCOS

  • Being overweight or obese - There’s actually a significant number of women with PCOS that are normal weight. Having PCOS can make weight maintenance more difficult, but not all women with it are considered overweight or obese.

  • Rapid weight gain – Again, weight is not a criteria for PCOS diagnosis. Rapid weight gain or difficulty losing weight could be a potential red flag that suggests PCOS, but cannot be used to diagnose it.

  • Infertility – Infertility has several causes so it should not be assumed that a woman having difficulty getting pregnant has PCOS. In fact, some women with PCOS don’t have trouble conceiving at all.

  • Elevated AMH level – At this time, an elevated AMH level (anti-mullerian hormone) cannot be used to diagnose PCOS. There is talk about this eventually being a criteria for diagnosis – women with PCOS generally have levels 2-4 times higher than other women their age.

  • Elevated LH/FSH Ratio – Women with PCOS usually have ratios of luteinizing hormone (LH) and follicle stimulating hormone (FSH) of 2:1 or 3:1 or more. Women without PCOS generally have levels closer to 1:1. Although this is not a diagnostic criteria for PCOS, some providers like to check these to somewhat solidify or confirm the diagnosis. This practice is not recommended at this time.

  • Having just one criteria – Meeting 2 out of the 3 criteria is necessary for a PCOS diagnosis. Some women have hirsutism for reasons other than PCOS. Some women don’t ovulate regularly and don’t have PCOS. It sounds strange to say, but some women have polycystic ovaries and don’t have polycystic ovary syndrome. Just because you meet one criteria does not mean you have the syndrome.

What to Do with this Information

Now that you’ve been schooled on diagnosing PCOS, what do you do if this sounds like you? PCOS needs to be evaluated and diagnosed by a physician or an advanced practice provider (nurse practitioner or physician’s assistant), not self-diagnosed. Many women do not feel heard when discussing the potential of PCOS with their provider, myself included. If you feel your doctor is missing something, or not doing enough testing, speak up. Consider getting a second (or third or fourth or fifth) opinion if needed. Ask your doctor how they made the decision on if you have the syndrome or not. If they’re not discussing these three criteria with you, it may be time to move on.

bottom of page