A Functional Approach to Thyroid Health

Updated: Oct 9, 2018



Thyroid problems are becoming too common in modern society, and yet sadly many people take thyroid health for granted. Our thyroid is the primary gland responsible for controlling metabolic rate and basic physiological function, and thyroid hormones impact all major systems, in fact every single cell has a receptor for thyroid hormone.

Thyroid hormone directly acts on multiple body systems like the brain, gut, the cardiovascular system, liver, gallbladder, and influences the metabolism of steroid hormones, glucose and protein metabolism, body temperature regulation, lipid and cholesterol metabolism and more. When thyroid function is compromised, symptoms can manifest throughout the body.

The below stats speak for themselves. It’s estimated that women are 5-8 times more likely than men to have thyroid problems, with one in eight women being likely to will develop a thyroid disorder during her lifetime.


*Stats Image from Kresser Institute ADAPT Framework

Thyroid Problems Affect The Whole Body

The thyroid gland is like the motor of the body, hyperthyroidism causes it to run faster, whereas hypothyroidism causes it to slow down. Symptoms of thyroid malfunction can vary depending on whether the thyroid is over or under active, and whether there is an autoimmune response involved with conditions like Hashimotos or Graves Disease. Hyperthyroidism is less common than hypothyroidism, and is often a more serious condition, because of the increased the risk of heart attack, stroke, and death. Undiagnosed or poorly managed thyroid issues are hazardous for health given the multiple body systems that rely on thyroid hormone, and in the scientific literature thyroid issues are associates with infertility and poor labour outcomes, osteoporosis, cardiovascular disease and more.


The Incomplete Conventional Approach to Thyroid Treatment

The conventional medical model rarely runs a comprehensive thyroid panel, and often relies on simply measuring Thyroid Stimulating Hormone (TSH) as a sole indicator of thyroid function. But this is a flawed approach for multiple reasons, and fails to address the complexity of thyroid issues. While TSH may be the most sensitive marker for thyroid function, TSH tells the thyroid gland to produce thyroxine (T4) and triiodothyronine (T3) which are the primary circulating thyroid hormones. T4 is produced in significantly greater quantities to T3, but T3 is approximately five times more biologically active than T4.

Measuring only a few markers, or only measuring TSH for thyroid function, fails to appreciate the multiple connected systems that influence the thyroid, thyroid conversion, thyroid binding globulin issues, or receptor issues, as well as any immune response. For example:

  • If TSH is in the range, patients will often be misdiagnosed as fine, and sent on their way without further investigation of other thyroid markers, or why the patient is unwell. In the traditional medical model, sub clinical lab values are often neglected, meaning a client will often miss early detection, and can only be treated once they have overt thyroid problems.

  • In cases of where TSH is high, and free thyroid hormones T3/T4 are low, the patient is often given exogenous hormone prescription, and again sent on their way without identifying the underlying cause of why the thyroid hormone was low.

  • And in cases where TSH is low and thyroid hormones are high, the conventional model seeks to suppress thyroid production with drugs, radiation or surgical removal of the thyroid gland, often permanently destroying its ability to produce thyroid hormone.

A common problem a patient with hypothyroidism on prescription T4 hormone may experience is facetious hyperthyroidism, which occurs from excess hormone replacement. This often occurs when there has been no investigation into the underlying cause of low thyroid, and over time the patients symptoms get worse, and so the dose is simply increased. Eventually the dosage of thyroid is so high that the patients own production of thyroid hormone is suppressed, but their T3 production is so high they experience hyperthyroid symptoms like anxiety, weight loss, palpitations, and increased risk for the dangerous conditions associated with hyperthyroidism.

Thyroid Replacement Therapy Rarely Works Alone

Many patients who just take thyroid hormone don’t get better and/or they need higher and higher doses over time. Monotherapy with T4 hormone or levothyroxine, it is the standard of care to replace low thyroid levels. But T4 is the precursor or the storage hormone, and needs to be converted into T3 (the active hormone) to have an effect.

The concept of T4 therapy is that it is safest to allow the body to make the conversion to T3 as required. But this approach is problematic for many reasons, because there are many factors that reduce T4-to-T3 conversion, like inflammation, HPA axis dysregulation, gut dysfunction, aging, iron excess or deficiency, fasting, nutrient deficiency, low testosterone, and genetics.

‘90% of patients with hypothyroidism have Hashimoto’s, which is an autoimmune inflammatory condition, and inflammation inhibits the conversion of T4 to T3!’

– Chris Kresser ADAPT framework