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The PCOS Newsletter is a weekly publication answering one PCOS question at the time so we can be empowered by knowledge.

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A guide to PCOS Diagnosis

Updated: Feb 6, 2023

Hi, This is Francesca from The PCOS Newsletter where we provide answers to complex PCOS questions in a concise and easy-to-understand format. Have a question? Ask it here.

Today’s question:

How can I be sure I have PCOS?

The answer:

The diagnosis of PCOS is not an easy endeavour, and you might know that already. That's because it's a syndrome, not a disease.

Syndrome = A collection of signs and symptoms known to frequently appear together that suggest the presence of a system dysfunction, without a known cause.

Disease = Has a known cause, clear and consistent symptoms, and accepted treatments.

The problem with PCOS is that we don't know why it’s happening, so it can look different from person to person. For me, it took 8 years to finally get diagnosed, and I've never had a normal menstrual cycle. But don't worry, I'm here to help you navigate the diagnosis process.

Before we get into the nitty-gritty

Let's quickly go over the main function that PCOS affects: the communication between the brain and the ovaries that controls reproduction, also known as the hypothalamic-pituitary-ovarian (HPO) axis. PCOS disrupts this communication by causing an excess of androgens and problems with ovulation.

Here's the deal:

To be diagnosed with PCOS, you need to meet two out of the following three criteria, known as the Rotterdam criteria:

  1. Scans show polycystic ovaries (little cysts on your ovaries)

  2. Signs of excess androgen levels or a blood test that shows high androgen levels

  3. (mainly testosterone)

  4. Irregular or infrequent periods, which can indicate that you're not ovulating

Ok, where does insulin resistance come in?

I know, I know. Insulin resistance is often talked about in relation to PCOS, but it's not one of the criteria for diagnosis. The reason is that high insulin levels can affect your androgen levels, which then causes the symptoms of PCOS. Don't worry, we'll dive deeper into this in a future newsletter.

My blood test results are fine, why did I get diagnosed with PCOS?

There are a few blood tests that are recommended mainly focused on LH, FSH, and Testosterone levels to help diagnose PCOS. However, the nature of hormones is that they are pulsatile throughout the day and change depending on where you are in your cycle. As a result, they become very hard to measure accurately as it is highly dependent on when you take the test. I have never had out of range blood test results, but I do have a PCOS diagnosis. A doctor can diagnose on a purely observational basis as your symptoms might speak louder than blood test results. That's why it's important to keep track of your symptoms and know your body. As a society, we depend too much on numerical values that skew with the ability to truly be in tune with ourselves.

Ok, so what symptoms should I be looking for?

  • Polycystic ovaries - most of the time this doesn’t give any symptoms, but sometimes it can cause pelvic plain, bloating and pressure.

Please note that you can have polycystic ovaries without having PCOS. It is important to make this distinction as cysts on your ovaries could be totally normal without the attached PCOS symptoms. They can also have other causes so it is important to clarify these with your doctor.

  • Excess androgens - this usually shows up as unwanted hair (read more about why here), acne, deepening of the voice, irregular periods and hair loss.

  • Irregular periods - A cycle that is longer than 35 days and shorter than 23 days can be considered irregular. This is the easiest way to spot something is not quite right but it’s important to remember that there are women with PCOS that have regular cycles. You can also have missing periods without having PCOS due to stress, over exercising and other conditions. It is always key to look for cluster of symptoms and not take one individually.

  • Insulin resistance - Signs of IR usually are weight gain, difficulty to maintain a healthy weight, cravings, skin tags (you can read more about it here), frequent urination, feeling of tiredness and excessive thirst.

Given it manifests in a multitude of ways (just to make it all complicated), in 2012 it was proposed to divide PCOS into 4 phenotypes:

  1. Phenotype A: A woman with PCOS that displays all of the three criteria above: polycystic ovaries, excess androgens and failed ovulation (irregular periods). This type of PCOS is usually the most pronounced and associated with higher BMIs, insulin resistance, acne etc.

  2. Phenotype B: This type is characterised by excess androgens and failed ovulation but without the existence of cysts on ovaries.

  3. Phenotype C: Women that experience signs of excess androgens and have polycystic ovaries but are ovulating and have regular periods. This is a much milder form of PCOS.

  4. Phenotype D: This type of PCOS is characterised by a lack of ovulation and the existence of cysts on ovaries but without excess androgens levels.

Lastly, NHS clearly states: “A diagnosis of PCOS can usually be made if other rare causes of the same symptoms have been ruled out”. However, in my experience, no other causes have been considered. I recommend insisting and asking at follow ups ups to ensure they have ruled out other conditions.

It’s a bit complicated…

You might have realised by the time you got to this paragraph that this condition is quite complex. Anyone that tries to explain this in a simplistic way will leave out a lot of details. This is the purpose of The PCOS Newsletter, to allow you to immerse yourself in the complexity of it so you don’t have superficial knowledge about it. With each issue I intend to go deeper into these differences so we embrace complexity rather than run away from it. Please don’t feel discouraged, our bodies are very complex systems that do A LOT of things, so it’s only natural to dedicate the time needed to get to know it.

Who can give a diagnosis?

Bear in mind that nutritionists, health coaches, dieticians are NOT qualified to offer you a PCOS diagnosis. Please ensure you speak to your GP and specialists to ensure you are offered the most accurate diagnosis. Being unsure you have it can cause a lot of unnecessary anxiety (and us women have enough of it as it is).

I hope this issue shines some light on the diagnosis and complexity of PCOS, but I am quite sure it has sparked a lot of other questions. Please don’t hesitate to reply to this email, leave a comment or submit your questions here, so we can explore them in further detail as we go along.

See you next Sunday,



Hart, R., Hickey, M., & Franks, S. (2004). Definitions, prevalence and symptoms of polycystic ovaries and polycystic ovary syndrome. Best Practice & Research. Clinical Obstetrics & Gynaecology, 18(5), 671–683.

Johnstone, E. B., Rosen, M. P., Neril, R., Trevithick, D., Sternfeld, B., Murphy, R., Addauan-Andersen, C., McConnell, D., Pera, R. R., & Cedars, M. I. (2010). The polycystic ovary post-rotterdam: a common, age-dependent finding in ovulatory women without metabolic significance. The Journal of Clinical Endocrinology and Metabolism, 95(11), 4965–4972.

Naz, R. K. (2014). Polycystic ovary syndrome current status and future perspective. Frontiers in Bioscience (Elite Edition), E6(1), 104–119.

NHS, Polycystic ovary syndrome - Diagnosis. (2022).

NICE, Polycystic ovary syndrome. (2022). Https://

Witchel, S. F., Oberfield, S. E., & Peña, A. S. (2019). Polycystic ovary syndrome: Pathophysiology, presentation, and treatment with emphasis on adolescent girls. Journal of the Endocrine Society, 3(8), 1545–1573.

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