Why most doctors get thyroid testing all wrong

The sad fact is, conventional doctors have been taught to look at one number—and one number only—when evaluating a patient’s thyroid function. And that’s their thyroid stimulating hormone (TSH) levels. As a result, many people have an underactive thyroid that goes unrecognized.

So I was pleasantly surprised when I came across a recent article suggesting that perhaps it’s time to reevaluate this approach…

TSH is the weakest link

A new review and meta-analysis of more than 50 different studies showed that thyroid hormone levels—and free thyroxine (FT4) levels, in particular—are more strongly and consistently linked with clinical symptoms of low thyroid than TSH.

Not only that, but get this (and I quote): “We found no indication of, or reference to, any work that suggested that TSH levels consistently indicate thyroid status of any organ or tissue more strongly than thyroid hormone levels.”

BAM! There you have it, folks. Another conclusion in my corner.

This analysis looked at free T4, free and total T3 (triiodothyronine), and TSH. Roughly half of the studies found that serum free T4 levels were tied to common symptoms and conditions linked with low thyroid. And levels of T3 also had strong ties to thyroid symptoms in more than half of the study subjects.

Meanwhile, not one of the studies showed TSH to be a stronger clinical indicator than either of these other parameters. So clearly, TSH is not the hormone your doctor should rely on to assess you for hypothyroidism…

(On a side note, I will point out that this is the only hormonal condition for which we look at levels of the controlling hormone—which, in this case, is TSH—to decide whether and how to treat. In every other case, we look at the circulating hormones themselves. That’s just common sense, if you ask me—which is why I always test for the full array of thyroid hormones.)

What smart testing looks like

The proper diagnosis of hypothyroidism is an important issue. Especially because there are many ways it can present itself, clinically.

You can experience the usual symptoms of low thyroid, like sluggishness, fatigue, dry hair and skin, depression, and constipation. But there are a whole host of other serious complications associated with the condition—like atrial fibrillation, osteoporosis, fractures, cancer, dementia, and increased risk of death, to name a few.

That’s not a short list, by any stretch. Still, I can’t tell you how many times I’ve heard the same story from patients. And subsequently, sent them for proper thyroid workup that their doctor never ordered.

Comprehensive thyroid testing should include bloodwork for free T4, free T3, reverse T3 and thyroid auto-antibodies. Then and only then can you begin to adequately determine an appropriate treatment plan.

But even then, as a doctor, I have to listen to the patient. And if they have all the signs and symptoms of a certain illness, but the numbers don’t add up, well… I go by the adage that I am treating the patient, not the test results. And that’s especially true for thyroid conditions.

So please—at the very least, ask your doctor to give you all the tests necessary to make an accurate diagnosis. And if they won’t, put that mask right back on and go see a doctor who will.

P.S. As one of your body’s main energy regulators, your thyroid plays a vital role in most of your biological functions. Which is why good thyroid health is so important. So, I explain everything you need to look for—and how to stop hyperthyroidism, in particular, before it turns deadly—in the August 2018 issue of my monthly newsletter, Logical Health Alternatives (“The lesser-known, more lethal thyroid disease”). Not yet a subscriber? Become one today!


“Time to Switch From TSH to T4 for Assessment of Thyroid Function?” Medscape Medical News, 05/18/2020. (medscape.com/viewarticle/930672)