What blood tests should you have for PCOS?
Although blood tests are not required for the diagnosis of PCOS (read about diagnosing PCOS here), they can help rule out any other hormonal conditions which could be causing your symptoms.
The difficulty can be getting your GP to send you off for blood tests and ensuring they send you for the right blood tests. Unfortunately, many GP’s don’t know a lot about PCOS and how to manage the condition or what to look for. I hope that this article arms you with the correct information to enable you to have an informed conversation with your GP about what blood tests would be most beneficial for you.
This is by no means an extensive list, there are many other things we can test for with PCOS, however anything more specific will be linked to your symptoms and would need to be discussed with a PCOS specialist or your GP.
Tests to exclude other conditions which have similar symptoms:
Thyroid stimulating hormone
Other tests to confirm the diagnosis and any hormonal imbalances:
The most accurate way to check testosterone levels is to test DHEA-Sulphate, testosterone levels fluctuate throughout the day therefore not giving you an accurate reading. DHEA-S remains the same for a few days and will therefore provide a more accurate reading. Elevated testosterone levels are often the cause of excessive hair growth, acne, and irregular menstrual cycles as it can prevent the maturation of follicles in the ovaries.
LH & FSH
These are both involved in ovulation and your ability to fall pregnant. FSH can be low in PCOS and LH can be high, often due to increased insulin and testosterone levels which stimulate the pituitary gland to produce more LH than FSH. High LH levels can prevent regular ovulation. The ratio of these hormones is important, ideally, we are aiming for a ratio of 1:1, we often see ratios of 2:1 or 3:1 (LH to FSH) in women with PCOS.
Liver Function test
If insulin resistance is present and not managed damage can be caused to the cells of the liver. It is important to check for any damage and help identify whether lifestyle changes need to be made to better manage insulin and glucose levels to prevent further damage to the liver.
White blood cell count
Our white blood cell count can help us identify inflammation which we often see in women with PCOS. This can indicate that might benefit from supplementing with things like Omega 3 to help reduce inflammation and make lifestyle changes that help reduce inflammation.
Here we are looking for insulin resistance as well as prediabetes or diabetes. PCOS increases your risk of developing diabetes so it’s important to pick this up as early as possible to ensure you get the right treatment and manage your lifestyle accordingly to prevent developing diabetes in the future. Most GP’s will send you for an HbA1c test (this looks at your glucose levels over 3 months) which is great for identifying prediabetes or diabetes, but it does not always show us where there is insulin resistance. Glucose tolerance tests are slightly more accurate but not routinely checked as they involve drinking a glucose solution and then having blood tests at regular intervals for 2-3 hours afterward. Ask your GP about both tests, you might get lucky and be able to get both done.
This includes things like triglyceride levels and cholesterol levels. With PCOS there is an increased risk of developing heart disease which is why your GP needs to check these indicators to ensure you make the correct lifestyle changes to keep your heart healthy.
When it comes to interpreting your results, it’s important to note that most GP’s use reference ranges when looking at the results of your blood tests. Reference ranges are not based on what is considered normal or optimal, instead they are the levels that 95% of the normal population fall in to – this includes women of all ages and stages of life including postmenopausal. It is for this reason that women who are clearly showing signs of elevated testosterone levels (excess facial hair, acne) get a ‘normal’ testosterone reading. Be sure to take your results to someone who specialises in PCOS and will be able to interpret your results correctly.
If you are not getting anywhere with your GP you can request to see another GP, alternatively it might be worth working with a health care professional (preferably one that specialises in PCOS) who can communicate with your GP on your behalf and request these blood tests.