Is Your Thyroid Actually Fine? Why TSH Alone Misses 90% of Hypothyroid Root Causes
Episode Summary
Colin Renaud, PA-C walks through the thyroid in depth, covering why it is one of the most under-managed conditions in conventional medicine, how the gut directly affects thyroid hormone conversion, why Hashimoto's (autoimmune thyroid disease) is the root cause of roughly 90% of hypothyroidism in the US, and what a complete functional medicine thyroid workup actually looks at compared to the single TSH test most patients receive. The episode includes a myth-or-fact rapid-fire segment, a case study of a patient whose antibody levels nearly halved after going gluten-free, and a live Q&A covering ANA antibodies, fecal transplants, and whether thyroid problems are ever reversible. The central message is that treating only TSH with levothyroxine while ignoring antibodies, conversion, gut health, and nutrition is a major failure of the standard model.
Key Topics
- 1
What the thyroid is, where it sits, and how it regulates metabolism and energy at the cellular level
- 2
T4 (inactive storage form) vs T3 (metabolically active form) and why the conversion matters
- 3
Why looking at TSH alone misses most of what is actually happening with the thyroid
- 4
Why about 90% of hypothyroidism in the US is autoimmune (Hashimoto's)
- 5
How Hashimoto's progresses: antibodies infiltrate thyroid tissue and destroy it over time
- 6
The gut-thyroid connection: 20% of T4-to-T3 conversion is influenced by gut bacteria
- 7
Key nutrients for thyroid function: iodine, selenium, zinc, iron, tyrosine, vitamin D
- 8
Why gluten is one of the most common triggers for Hashimoto's
- 9
Environmental toxins, chronic stress, obesity, and gut permeability as thyroid disruptors
- 10
How the conventional model is structured (TSH only, levothyroxine, follow up in 3 months) and why it fails patients
Quotable Moments
“I have had patients say that their doctors blatantly said, 'Well, it doesn't matter how you feel. It's what your values say.' That's a slap in the face for a patient.”
“Hashimoto's is not levothyroxine deficiency. Pathology in the body is not a deficiency of a medication.”
“We do things so regularly that we sort of think the whole world is doing it. But we're so outside the box that it's like, really, your doctor doesn't do this? It's kind of just shell shocking sometimes.”
“Chronic illness doesn't occur overnight. People diagnosed with Alzheimer's at 60 probably started having an issue at 40. Same with diabetes. Same with thyroid disease.”
“If somebody ever tells you this is the only thing you can do, find a new doctor. If somebody is telling you this is the only option, that's not true.”
Treatments Mentioned
FAQ
Thyroid FAQ
TSH only shows whether medication is suppressing the stimulating hormone. It does not reveal whether your body converts inactive T4 into active T3. Many patients on levothyroxine have suppressed TSH but inadequate T3. A full panel with free T3, free T4, reverse T3, and antibodies gives the complete picture.
Approximately 90% in the United States. This means the immune system is producing antibodies that gradually destroy thyroid tissue. Most hypothyroid patients have never been tested for antibodies and do not know they have an autoimmune condition.
About 20% of T4-to-T3 conversion is influenced by gut bacteria. Key nutrients (iodine, selenium, zinc, iron, tyrosine) must be absorbed through a healthy intestinal lining. Impaired gut health reduces both nutrient absorption and hormone conversion.
Yes. Gluten is one of the most documented dietary triggers for Hashimoto's. In one case, a patient's thyroid antibody levels nearly halved after going gluten-free for three months. Those with autoimmune susceptibility are at significantly higher risk.
Hashimoto's is highly manageable. With proper intervention, antibody levels can come down significantly by addressing gut health, gluten, stress, toxins, and nutritional deficiencies. Genetic susceptibility means the term "curable" is used cautiously.
Iodine for T4 synthesis, selenium for T4-to-T3 conversion, zinc for hormone production, iron for autoimmune regulation, tyrosine as a building block, and vitamin D for overall function. Deficiency in any can impair thyroid performance even on medication.
Related Service
Learn More
Autoimmune Diseases
Functional medicine for autoimmune diseases in South Portland, ME. Hashimoto's, lupus, Crohn's, POTS, and complex conditions. Root-cause testing and personalized protocols.
