Subclincal Hypothyroidism - Check Your Thermostat

Christina Carreau BA, ND

There is currently a debate going on as to what the normal reference range for healthy thyroid function should be. This debate is between medical doctors, endocrinologists and naturopathic doctors. The outcome of this debate could have a significant impact on your health.

Let’s start with the basics.

The Thyroid Gland
The thyroid gland is a small butterfly shaped gland located below your Adam’s apple. The role of the thyroid is to make and store hormones that help regulate heart rate, blood pressure, body temperature, and the rate at which food is converted into energy (metabolism). Thyroid hormones are essential for the function of every cell in the body. Needless to say, this is a very important endocrine organ and one that significantly impacts our weight, energy and overall health.

Thyroid Hormones
Thyroid Stimulating Hormone (TSH) is produced by the pituitary gland (in the brain), which in turn, stimulates hormone production by the thyroid gland. In response to TSH, the thyroid gland produces the hormones Thyroxine (T4) and to a lesser degree, Triiodothyronine (T3).  The balance of these hormones plays a critical role in your overall health.

The Debate
The current medical ‘gold standard’ for assessing thyroid function is to measure the amount of TSH circulating in the blood. The ‘normal’ reference range for TSH by most labs in North America is 0.35 – 5.0.

In 2005, The American Association of Clinical Endocrinologists challenged this reference range, stating that a narrower margin (0.35 – 3.0) would help diagnose millions of people who suffer with mild or ‘subclinical hypothyroidism’. But what would they know, they are only the leading experts on hormone health?

So here we are, nearly a decade later and our normal reference ranges for TSH haven’t changed even though the leading scientists in the field pointed out the flaws in our current system 10 years ago. I point this out because it demonstrates how long change can take in our established medical system, which means we need to be more proactive with our health.

A study done in 2005 demonstrated that with the current TSH reference range (0.35 – 5.0) 5% of the population has hypothyroidism but if the upper range for TSH were lowered to 3.0 approximately 20% of the population would be diagnosed with hypothyroidism. That means that 15% of the population considered to have normal thyroid function today will be diagnosed with hypothyroidism once these standards are changed. These revisions could have a huge impact on the millions of people who are not being diagnosed or treated, because their test results are being evaluated according to the old reference range.

There are a lot of North Americans complaining of weight gain and low energy. And while certainly subclinical hypothyroidism isn’t the only cause, it is definitely a crucial one. So I encourage you to assess your own thyroid function by measuring your first morning temperature to ensure that you are not one of the millions being ‘misdiagnosed’.

Basal Body Temperature Tracking
As I mentioned earlier, your thyroid controls body temperature, so one of the ways to assess thyroid function is to track your temperature. Keep a thermometer by your bedside table along with a pen and piece of paper. Upon waking, (before drinking water or going to the bathroom or doing anything at all) take your temperature and record it along with the time of day. Do this for an entire month to get an accurate representation of thyroid function. If your temperature is consistently below 37 degrees Celsius, your thyroid gland may be in need of support.

Subclinical Hypothyroidism – A Growing Problem
As a naturopathic doctor, I was taught to treat subclinical hypothyroidism in patients demonstrating signs and symptoms of hypothyroidism, a TSH level higher than 2.0, and a basal body temperature lower than 37 degrees.

The symptoms of subclinical hypothyroidism and hypothyroidism are extensive but I will list a few here to give you a rough idea of what to look for.

Weight GainConstipationInfertility
FatigueAnxietyCarpal Tunnel
HeadachesDepressionMuscle Aches
Fluid RetentionIrritabilityIrritable Bowel
Hair LossElevated cholesterolAcid Reflux

The list goes on and on and as you can see an underfunctioning thyroid gland can affect a number of different systems in the body.

Final Thoughts
It is my opinion that disease and illness are evolving at a faster rate than medicine and that this is creating  ‘gaps’ in our medical system. These gaps mean that people who feel ‘unwell’ – tired, overweight, whatever the case may be, are sometimes told that they are fine, as their labs are within ‘normal’ reference range. You know your body better than your medical doctor or your naturopathic doctor, so if you think there is something wrong with you, then there probably is.

The point of this article isn’t to disregard years of medical science nor is it to make you paranoid that your thyroid gland is under-functioning. Rather, the point is always to help educate you on the subject, so that we can all play a more active role in our health.

‘Doctor as Teacher’ is one of the guiding principles of naturopathic medicine and I firmly believe that education in terms of diet, lifestyle, stress, hormone balancing, etc. is the starting point to help fill these gaps within our current model of medicine. Preventative medicine is the medicine of our future.