Understanding your thyroid markers can be confusing, especially when your doctor tells you that your levels are normal.

I love that we are seeing more and more people taking responsibility for their own health, rather than pinning everything on their annual or biannual blood test results. The reality for many is that blood values may well appear normal, whilst daily debilitating symptoms may be signalling a problem long before numbers go out of range.

Making sense of your thyroid hormone

Believe me when I say this is so incredibly common and I too encountered the frustration of having to make sense of my symptoms whilst blood test after blood test came back as ‘normal’.

So how are you supposed to understand your thyroid markers when things appear to be working well? This is the question that so many of the women I have worked with over the years have pondered.

Let me unpack some of this for you.

How to make sense of your thyroid markers

Conventional vs Functional

First you need to understand that there is a distinct difference between functional testing and the way that conventional testing analyses thyroid function. In functional medicine we like to understand the full picture in order to make sense of someone’s symptoms. This means that we look beyond what is visible on the surface, but instead go below the surface to see why things may be presenting the way they do.

Treating the tip of the iceberg is NOT going to address your health issues.

This is why a comprehensive thyroid panel is ESSENTIAL when you want to understand how to improve your health and thyroid function.

Secondly you need to understand the reference ranges and where you fit in with these so that finally you can establish an action plan to address the findings.

You may find it helpful to read more about how your thyroid works and how your body makes thyroid hormones. For now, let’s consider the key blood markers you need to consider.

Thyroid Stimulating Hormone (TSH)

TSH is a hormone secreted by the pituitary, a pea shaped gland located in the base of the brain. This means that it is NOT actually a hormone produced by the thyroid, yet it is one of two markers routinely tested in conventional medicine and for good reason. It tells us whether levels of thyroid hormone in the body are low or high. When levels of thyroid hormone in the body are low, the hypothalamus will instruct the pituitary to signal the thyroid to make more hormone. When levels of thyroid hormone are high or optimal, the hypothalamus will instruct the thyroid to stop making or converting thyroid hormone. This means that a high TSH indicates that levels of available thyroid hormone in the body are low and a low TSH indicates that levels are optimal.

Thyroxine (T4)

Your thyroid produces two hormones, one of which is T4. In fact, 80% of the thyroid hormone produced is T4. The interesting factor to consider is that T4 is your reservoir hormone. The thyroid produces it, so it can store it and then convert it into its active form when it is needed. So, whilst it is important to understand how much available T4 there is in your body, it does not actually tell you how much active thyroid hormone your body has available to enter the cells.

This means looking at T4 alone doesn’t really tell you whether you have sufficient thyroid hormone to support healthy metabolism and energy.

Triiodothyronine (T3)

Now we are moving below the surface and away from the visible tip of the iceberg. T3 is not routinely tested in conventional medicine and whilst there is sufficient literature to support this, it has failed millions of people worldwide when it comes to effective healthcare. As mentioned previously, your thyroid makes two hormones and T3 is the second hormone it produces. Whilst T3 only accounts for around 20% of the thyroid hormone your thyroid produces, it is THE ONLY thyroid hormone that can act on the cell to achieve the desired outcome. Whilst your body only produces around 20% of T3, your thyroid, liver, gut and peripheral tissues all convert T4 into T3 to ensure that you have sufficient levels of active hormone to keep your body healthy and in balance.

Not understanding your T3 levels, means that you are missing an important part of your thyroid jigsaw.

Reverse T3 (rT3)

Your body is working tirelessly to keep your body in balance. This means that it needs to be ‘in with the new and out with the old’. When there is excess thyroid hormone or old thyroid hormone that the body needs to get rid of, your body will convert it to rT3. During times of stress, this process may be sped up and more thyroid hormone may be shunted off for clearance instead of being converted to active thyroid hormone. After all, your body is dealing with a threat and thyroid hormone production, or conversion is just not going to be one of its key priorities. Whilst this marker is not always included in functional medicine, it can be helpful in particular cases where high levels of stress or inflammation are present.


Since around 80% of people with an under-active thyroid are autoimmune in nature, I personally think that one of the biggest failures of modern medicine is the lack of routine screening for antibodies. It may take up to 10 years for your thyroid numbers to go out of balance before you realise that you have an autoimmune condition (or in many cases you may never find out!). This is why this part of your blood test is so important! There are two types of antibodies that you can test for which will identify whether you have Hashimoto’s thyroiditis, and they are Thyroid Peroxidase Antibody (TPO Ab) and Thyroglobulin Antibody (TgAb).

The next steps

The truth is that it can be confusing, and this is why I have created a free guide for you to download to help you to make sense of your thyroid markers. I also go into detail in my programmes working with my clients to ensure that they understand exactly what they need to do to support themselves.

If you want to know what steps to take to reboot your thyroid, then book in for a free breakthrough call with me so we can discuss your health in more detail and look at the best possible options for you.

Nutritional Therapist Cheshire, Health, Nutritionist Cheshire, Functional Medicine Cheshire, Rootcause Solution