The 4 types of PCOS and how you know if you might have it
Updated: May 19
PCOS is becoming more and more recognized recently, and a lot of people are asking, "what is PCOS?"
PCOS stands for "Polycystic Ovarian Syndrome" and is a condition in which excess androgens cause you to stop ovulating, or have irregular ovulation, thereby causing irregular periods.
And along with irregular periods, other symptoms can include:
Facial hair growth
PCOS is a common diagnosis that can affect up to 10% of women! The main symptom is irregular periods. A lot of people actually get diagnosed with PCOS based on this symptom alone- so be careful that you meet the criteria for PCOS before getting a blanket diagnosis. If you have been diagnosed with PCOS, ask yourself, "How was I diagnosed?"
Rotterdam diagnosis criteria for PCOS include 2 out of 3 of the following:
Polycystic ovaries on ultrasound
Elevated androgens (either based on symptoms and/or from labs)
Anovulation or oligo-ovulation (the cause of irregular periods)
First of all, let's talk about those ovaries. What are polycystic ovaries?
The cysts seen on an ultrasound aren't true "cysts." They're actually immature follicles (eggs) that appear to look like cysts.
Under normal conditions, your ovary gets the signals from your brain to mature and release an egg every month. The maturation process takes about 90 days. At any given time, an adult can have up to 12 follicles in their ovaries that are ready for maturation and ovulation. One of those follicles will become dominant and larger than the others and will suppress the others for the rest of that cycle. The rest of the follicles (that aren't the chosen one) get reabsorbed.
In anovulatory cycles (like in PCOS), no dominant follicle is formed because the full signals for maturation are suppressed, likely due to excess androgens. Instead each of the follicles continue to grow just a little and you end up with several undeveloped follicles (aka "cysts").
Image: Fertility Center SA
Types of PCOS
Another important note is that there are multiple types of PCOS. The most commonly seen one is insulin resistant PCOS, but there are also other, less common, types of PCOS.
Insulin resistant PCOS: 60-70% of those with PCOS will have this type.
This is a result of elevated insulin levels impairing ovulation and causing your ovaries to produce too much testosterone instead of estrogen.
High insulin levels can also stimulate your pituitary gland to make more luteinizing hormone (LH) which can also stimulate androgen production.
And lastly, elevated insulin causes a decrease in sex hormone binding globulin (SHBG) which results in more free testosterone in your body.
You likely have insulin resistant PCOS if you meet all the criteria for PCOS (irregular periods + high androgens) and have elevated insulin levels.
Post-Pill PCOS: This one is exactly what it sounds like and can happen for a few different reasons.
Hormonal birth control can cause or worsen insulin resistance. So this may lead to insulin resistant PCOS.
Hormonal birth control suppresses ovulation (which is literally the point of it), and for most, ovulation resumes once you discontinue it. But for others, it may take months for that hypothalamic-pituitary-ovarian (HPO) axis to communicate again and start ovulating.
Getting off low androgen index birth control pills can cause a rebound surge in androgens. These androgen levels should decrease again after a couple years. But in the period when they're elevated, you may qualify for a PCOS diagnosis.
Inflammatory PCOS: When your PCOS isn't related to insulin levels or coming off the pill, then we look to other inflammatory conditions that might be causing issues with ovulation.
Inflammation plays a role in all types of PCOS, but in inflammatory PCOS, it's the main driver of symptoms.
Inflammation can be due to smoking, gut health issues and inflammatory foods, environmental issues, or other inflammatory conditions like autoimmune diseases.
You likely have inflammatory PCOS if you don't have insulin resistance, you didn't get off the pill, and you have issues like:
Fatigue that's unexplained
Brain fog and/or recurring headaches
Skin issues (psoriasis, eczema, cystic acne, etc)
This one occurs when your testosterone levels are normal, but your DHEAs levels are elevated (barring other reasons for your DHEA levels being elevated, this is the most likely diagnosis).
This is not driven by insulin resistance or impaired ovulation. It's caused by an abnormal stress response (AKA HPA axis dysfunction).
The biggest tool for addressing this type of PCOS is going to be stress management.
You likely have this type of PCOS when you meet the criteria for diagnosis of PCOS but don't have insulin resistance, aren't coming off the pill, and don't have any inflammatory symptoms.
It's important to know what type of PCOS you have because this dictates what therapies will work. Addressing insulin resistance with metformin when you don't have insulin resistant PCOS will not be useful for you.