What I Wish Everyone Knew About The Thyroid: A Functional MD Explains

As a doctor of integrative and functional medicine, I know that proper diagnosis and treatment is crucial, since undiagnosed low thyroid can lead to many common and serious health conditions.

The thyroid is intimately connected to every system in the body. It communicates by secreting two hormones T3 and T4. While T4 is the majority of what is released, T3 is much more active and necessary for cells to do work. T4 must go through a conversion process to be activated to T3.

Without the proper amount and balance of hormones, patients may experience symptoms such as constipation or diarrhea, sleep disturbances, mood swings, anxiety, high cholesterol, weight gain, depression, bloating, hair loss, immune dysregulation and even fertility struggles.

Plus, patients suffering with untreated low thyroid may be at a higher risk of developing serious conditions like heart disease and Alzheimer’s disease.

But I also see another side to this. If your thyroid is low or imbalanced, it's a good indicator that something else is off in your body. There are many conditions that often go totally unnoticed but may cause thyroid dysfunction. For example, common genetic changes affect detoxification pathways, preventing the body from excreting toxins it’s routinely exposed to.

Heavy metal toxicity is another problem becoming much more common and it, too, can affect thyroid health. Some metals affect receptors in the body that catch and pull in thyroid hormones while others may trigger autoimmune attacks on the thyroid and other organs. Still others could block the thyroid from using iodine, which is necessary for hormone production.

And issues like leaky gut and food intolerances could spark autoimmune disease, the leading cause of low thyroid today. Dysbiosis, or imbalances in the bacteria making up the gut microbiome, can also have disastrous effects, affecting intestinal function, inflammation levels, absorption of nutrients, and immune system regulation — all of which affect thyroid function.

Typically, a routine thyroid panel only looks at TSH and in some cases T4. The gold standard for diagnosis is considered to be an elevation in TSH levels as the best possible determinant of low thyroid function. However, the test may not be adequate for all people.

I find there are many conditions that actually suppress TSH levels, making them appear normal and rendering the standard test ineffective. What that means for patients is their conditions are overlooked, they receive a wrong diagnosis, or no diagnosis at all and miss out on needed treatment.

I recommend seeking out a TRH stimulation test, if possible. When used in conjunction with a full thyroid panel, I believe there’s a better chance of making an accurate diagnosis. In my experience, the best thyroid panel would include TSH, free and total T3, free and total T4, reverse T3, levels of antibodies to thyroid tissue, plus indirect markers like homocysteine, alpha and beta carotene, and cholesterol. When taken together, it can give a deeper understanding of thyroid function and overall state of the body.