The Sub-Clinical Hypothyroidism Controversy

Are symptoms of an under active thyroid gland enough to diagnose hypothyroidism?

What is Sub Clinical Hypothyroidism?

A number of people have thyroid blood tests that show mild elevation of thyroid stimulating hormone (TSH) and normal levels of T4 and T3 thyroid hormones.

Does this represent early stages of an underactive thyroid or are other reasons involved?

Should thyroid hormone treatment commence or is it best to wait until all numbers are definitely abnormal and a diagnosis of hypothyroidism is proven?

What do the British Medical Journal (BMJ) Guidelines Say?

A large thyroid study of people with mild changes in thyroid function blood tests was published in the BMJ in May 2019.

A panel of clinicians, including Professor Mieke van Driel, an Australian GP academic, issued a “strong recommendation” against the therapy in adults with only slightly elevated TSH levels where the TSH was between 4 and 10mIU/L, and free thyroxine levels within the normal range.

“Thyroid hormones do not lead to important benefits for adults with subclinical hypothyroidism for quality of life or thyroid-related symptoms including weight gain, depressive symptoms and fatigue,” they wrote.

According to Professor van Driel, even putting patients on a trial of thyroid hormone could generate “unwarranted” lifelong therapy. “We saw that internationally. The prescription and consumption of thyroid hormone was increasing when the incidence of hypothyroidism was not,” she said.

NB This advice does not apply to pregnant women, those trying to conceive, or those with TSH levels above 20mIU/L.

What Do The British Thyroid Association and Society for Endocrinology Say?

The British Thyroid Association and Society for Endocrinology disagree with the above BMJ thyroid guidelines.

They claim that patients may miss out on crucial early treatment and therefore progress to hypothyroidism.

“A particular concern … is that primary care physicians may now dismiss patients with subclinical hypothyroidism rather than institute ongoing surveillance, potentially resulting in some patients with progression of hypothyroidism being deprived of treatment.”

They also stated that the BMJ review was biased towards patients aged 65-plus. There was not enough evidence for the panel to make recommendations for younger age groups.

My Opinion

I see lots of people with symptoms of an underactive thyroid gland. The symptoms are many and varied. The reality is that symptoms alone are not specific for hypothyroidism and other causes need to be excluded. The diagnosis does need to be clearly confirmed with blood tests.

Other common reasons for symptoms of fatigue, weight gain and mood problems include digestive problems, stress and low iron levels. Mild changes in thyroid function blood tests are often secondary to these three underlying causes.

Borderline thyroid blood test results are not enough to justify life-long medication. Blood tests can easily be monitored and thyroid hormone replacement can addressed later if needed.  Integrative medicine with a holistic range of nutritional supplements, diet and lifestyle advice can make a significant difference to your overall health and wellbeing.