Why it may be time to get your thyroid checked…properly!

When a client has thyroid related symptoms but tells me they’ve been tested and told they are ‘normal’, alarm bells go off for me!

The thyroid is a small, butterfly shaped gland in the front of the throat, but despite being small in size it produces hormones that influence every cell in our bodies. These hormones have a vital role in regulating metabolism, which is the rate at which our bodies convert food and oxygen to energy. It’s this energy that powers our cells to do their job, whether it’s making our heart beat, our muscles contract or our brain function. Every cell, everywhere in our body has a thyroid receptor so if your thyroid isn’t functioning optimally, chances are, neither are you.

Too much hormone production and everything speeds up leading to symptoms including unintended weight loss, anxiety, nervousness, insomnia and heart palpitations. Too little hormone production and everything slows down causing symptoms such as weight gain, fatigue, low mood and depression, constipation, cold intolerance, dry skin, and the list goes on.

So you’ll see, thyroid dysfunction can manifest as a diverse range of symptoms as well as a diverse degree of severity. This, along with insufficient testing, can mean that many people go undiagnosed or are misdiagnosed.

For instance, many of the symptoms overlap with mental health conditions such as anxiety and depression, and presenting with these symptoms could easily result in a prescription for antidepressants or antianxiety medication when in fact, an underlying thyroid problem could be the root cause.

Who is at risk?

There is a strong genetic factor when it comes to the thyroid so those with a family history of thyroid issues may be more susceptible to developing issues themselves.

Women are five to eight times more likely to develop thyroid disease than men and the risk increases as we get older, particularly during peri-menopause when hormones are going haywire!

Conventional testing

There are two key problems with the approach conventional medical doctors tend to take when testing thyroid function. Firstly, they typically only test TSH and if you’re lucky, T4. This misses other key thyroid markers and by not testing these you are not getting a full picture of how your thyroid is functioning.

Secondly, the reference ranges used are very broad. As long as you sit somewhere within this range, you will more than likely be told that there is no issue with your thyroid, even though you may be at the very top or bottom end and presenting with symptoms. It’s very much a case of treating the results rather than the person.

In functional medicine, we don’t want our clients to be ‘normal’, we want them to be ‘optimal’. This is why practitioners will recommend thyroid testing that looks at all the relevant markers, as well as using ranges that are shown in the research to relate to more optimal thyroid function.

Understanding thyroid markers

Let’s take a closer look at the different thyroid markers and what they do to emphasise the importance of getting the full story.

Thyroid stimulating hormone (TSH)

This literally does what it says on the tin. TSH is produced by the pituitary gland and stimulates your thyroid to produce thyroid hormones. Circulating thyroid hormones should be kept at a fairly constant level, so if they become too low (as in hypothyroidism/underactive thyroid), TSH can become elevated in an attempt to increase thyroid hormone production. Likewise, if circulating levels become too high (as in hyperthyroidism/overactive thyroid), TSH can drop in order to inhibit the release of even more hormones.

This is why most GPs will just look at TSH to determine thyroid function, without taking into account what may be going on further down the pathway.

The reference ranges for TSH vary across different countries and labs but typically anything between 0.5 and 5.0 mIU/L is considered normal. This is despite research indicating that anything above 2 – 2.5 mIU/L increases the risk of developing hypothyroidism.

When I’m working with a client, I would consider anything above 2 – 2.5 mIU/L to be less than optimal and would want to be supporting the thyroid.

T4 (thyroxine)

This is the predominant hormone produced by the thyroid gland, however it is a largely inactive form and therefore has little to no effect on your cells. If you are prescribed thyroid hormone replacement medication, it is usually Levothyroxine which is essentially T4.

In order to have any impact in your cells however, T4 needs to be converted to T3 (see below). If you have an issue with this conversion process, you may still be experiencing symptoms despite being on thyroid medication and/or despite your TSH and T4 results being ‘normal’. Yet typically your GP will not look beyond these two markers.

T3 (triiodothyronine)

This is the active form of thyroid hormone and the one that actually gets to work in your cells controlling the speed at which all your cellular processes happen e.g. energy production, body temperature, heart rate, hair and nail growth etc. The thyroid gland itself only makes a small amount of T3 with the rest having to be converted from the inactive T4 form.

This conversion takes place mainly in the liver, with a smaller amount being converted in the gut as well as locally in cells such as muscles, kidney and brain cells. Therefore, poor liver function or gut health, as well as deficiency in the nutrients zinc and selenium which are critical cofactors in this conversion process, can all influence how well you convert T4 to T3.

Reverse T3 (rT3)

This is an inactive form of T3. Chemically, it has the same structure just in reverse, like a mirror image. This means it is still able to dock on to thyroid receptors in the body but it doesn’t have any effect.

Why would your body do this? There are several reasons but a key one is stress. When you are stressed, your body gets the message to conserve energy so you have enough to deal with the ‘danger’, and one way to do this is to slow the rate of metabolism inside your cells. Hence your body has evolved to convert T4 to this fake T3 in these situations.

It’s actually pretty clever when you think about it, but it can be problematic in the long term and given many of us are living our lives with some degree of chronic stress, this is a very common contributing factor in both the development and maintenance of thyroid conditions. Not to mention, stress can actually inhibit the production of thyroid hormones in the first place!

Thyroid antibodies

There are two main thyroid antibodies, thyroglobulin (TG) and thyroid peroxidase (TPO). The presence of antibodies is an indicator of an autoimmune condition whereby your own immune system is attacking your thyroid gland by mistake. The two main autoimmune thyroid diseases are Graves disease and the more common Hashimoto’s disease.

Thyroid antibodies are not routinely tested and yet Hashimoto’s is the underlying cause of developing overt hypothyroidism in 90-95% of cases!!

If your GP does test for antibodies and they are positive but other thyroid markers are ‘normal’, it’s not uncommon to be told to just wait and see, and if you do (almost inevitably) develop hypothyroidism in the future, they’ll give you Levothyroxine at that point.

The problem with this approach is that firstly, it ignores the fact that you have an autoimmune reaction going on in your body which you could be proactively managing to help slow or even prevent progression to overt hypothyroidism, and secondly, whilst medication can help to manage your thyroid hormone levels, it fails to address the root cause of your thyroid dysfunction, which isn’t actually a thyroid issue but an immune system issue!!!

Testing all thyroid markers is therefore critical for understanding whether or not there is a problem, and if there is, where along the pathway it’s occurring. This helps to put in place a more targeted protocol depending on whether it’s a production issue, a conversion issue, an autoimmune issue or a combination.

How to get properly tested

In New Zealand, it is possible to get tested for TSH, T4, T3 and TPO antibodies via Labtests if you have a referral from your GP. It is therefore worth asking your GP for this if you suspect you may have thyroid issues. This will give you a pretty good picture of overall thyroid function however, as far as I am aware, it is not possible to be tested for rT3 or TG antibodies without using a private lab.

If your GP is not willing to refer you, or you want to get tested for all the markers to get the complete story, then please get in touch with me for details of how I can help.