Why standard thyroid testing is inaccurate

In my experience, many people show clinical signs of hypothyroidism, but their medical tests are ‘normal’.

It’s often because the tests being used by doctors are inadequate and don’t provide the whole picture.

This article is a really important read if you’ve been diagnosed with thyroid problems, or suspect you may be having them,

Hypothyroidism, where the thyroid gland is deemed to be underactive, causes all manner of symptoms, including:

  • Fatigue
  • Depression
  • Constipation, bloating and gas
  • Weight gain
  • Muscle cramps
  • Dry skin
  • Hair loss
  • Menstrual problems
  • Cold hands and feet

I’ve worked with many clients who had a cluster of these symptoms, yet their NHS thyroid test was fine.

To understand how thyroid function can be severely depleted despite normal blood tests, it’s important to look at thyroid physiology.

I’ll just use the abbreviations here as it’s much simpler that way!

Your thyroid gland sits in your neck, behind your windpipe and manufactures hormones called T4 and T3 (and others) that regulate your metabolic rate.

But the thyroid itself is only part of the jigsaw and it’s important to look at the whole puzzle if you want to rejuvenate thyroid health.

Here’s a brief outline of the puzzle:

An area of the brain called the hypothalamus monitors blood levels of thyroid hormones.

If levels fall too low, it sends a hormone called TRH to the pituitary gland with instructions to make TSH.

TSH is sent from the pituitary to the thyroid, telling the thyroid to make more hormones.

The thyroid gland itself produces T4 and T3 hormones, but mostly T4.

T4 isn’t particularly active in the body and has to be converted into T3.

Most of this conversion is done in the liver, with some also done by the bacteria in your gut.

T3 is about six times more active than T4. It enters your cells and acts like a throttle on your energy production.

If your thyroid hormone levels are a little high, your hypothalamus dampens its TRH production, which dampens TSH and slows thyroid hormone production.

Nutrients needed for optimal thyroid hormone production and conversion include tyrosine, iodine, zinc and selenium.

Common sense doesn’t prevail…

The series of steps is really just basic physiology. It’s nothing complex.

But when measuring thyroid function, the medical system will typically consider either TSH on its own, or TSH and T4.

If TSH is high, it’s interpreted as the brain’s attempt to yell at the thyroid gland to make more hormones because they’re too low.

Therefore, a HIGH TSH level is the accepted marker for LOW thyroid function.

The problem is that millions of people have hypothyroidism despite having a normal TSH level.


First, the ‘normal’ range for TSH is ridiculously wide at 0.3 and 3.0 uIU/mL (3.0 is obviously ten times higher than 0.3).

It’s clear that someone with TSH at 0.31 is in a completely different physiologic state than someone with TSH at 2.99, yet both are considered to be ‘normal’.

Second, thyroid hormone function, which causes symptoms, can be inadequate despite normal thyroid gland function.

In other words plenty of T4 is made in the gland but is not properly converted to T3 due to problems in the conversion process (e.g. selenium deficiency).

Third, under stress T4 can be converted into reverse T3, which sits in hormone receptors and prevents T3 from doing its job.

Again, thyroid gland function (T4) and TSH may look perfectly normal, but if rT3 is high, it’s likely to create hypothyroid symptoms.

Revisiting thyroid testing

It’s fairly clear from this basic description that a basic assessment of thyroid function should at least include measures of TSH, T4 and T3.

Just measuring TSH misses so many important nuances that it’s grossly unfair to base a diagnosis of thyroid disease on this single marker.

The immune connection

It’s also important to note that many, if not most, cases of hypothyroidism are autoimmune in nature.

This means that the immune system is attacking the thyroid gland, so it’s actually an immune disorder, not a thyroid problem.

Two test markers can be used to assess immune status as it relates to thyroid function, namely anti-thyroid peroxidase (TPO) and anti-thyroglobulin antibodies (Tg).

These markers can be added to a thyroid panel to increase the amount of information on which to base a rejuvenating protocol.

The reason medics don’t test these antibodies is that the findings don’t alter treatment.

As you may know, the only treatment offered is thyroxine, a synthetic version of T4 hormone.

Irrespective of reason for hypothyroidism, the only treatment is thyroxine, which is bordering on insane given the options available once we understand physiology.

Thyroid treatment may not require thyroid treatment at all! Instead, calming and balancing the immune system will allow the thyroid to function properly once again.

But this would be too difficult to do in the medical setting because it involves diet and lifestyle changes, detoxification, gut healing and careful supplementation with relevant nutrients.


A medical test that only looks at TSH is incomplete and misleading.

Even a test that looks at TSH and T4 may not reveal the full picture.

The bare minimum assessment should include TSH, T4, T3 and thyroid antibodies, with reverse T3 ideally added.

This way, you can see precisely where the functional block in thyroid function or metabolism is located.

You can then use a holistic programme that focuses on restoring function (not treating the gland).

A correctional programme must include diet, eating habits, detoxification, digestive healing and specific nutrient replacement.

Unless you have been on thyroid medication for many years, or had surgery on it, it’s completely reasonable to assume that you can restore function.

Would you like some help with your thyroid (or symptoms?)

As you know, I offer a case review and initial consultation so we can really focus on what’s creating your symptoms.

If you’re having difficulty with energy, feeling cold, hair loss, weight gain and other thyroid-related symptoms I’d love to assist you.

Learn more about booking a case review and initial consult here.



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