Why Do I Still Feel Tired Even With Normal TSH?
Looking Beyond TSH
You take your thyroid medication every single day. You go to the doctor. They run labs. And they tell you, “Good news. Your TSH is normal. Everything looks fine.”
But you are sitting there thinking, “If I am so fine, why am I still so tired?”
This is one of the most common questions I hear. And the answer is simple. TSH does not tell the whole story.
TSH is just one marker. For years, doctors were taught it is the only test they need to check thyroid function. But to see what is really going on, we need a complete panel.
Here is what we should be looking at in addition to TSH.
First, Free T3. This is the active hormone. It turns on your metabolism and gives you energy. Think of it as the gas pedal.
Second, Free T4. This is the storage form of thyroid hormone. Your body converts it into T3 when it needs it.
Third, Reverse T3. This acts like the brake pedal. It blocks energy production.
If we only look at TSH, we have no idea whether you are pressing the gas or the brake.
There is another piece of the puzzle we cannot ignore. Anti-thyroid antibodies.
We need to check for Hashimoto’s thyroiditis. It is the most common autoimmune disorder. If your antibodies are high, your immune system is attacking your thyroid. That causes symptoms even when your TSH looks perfect on paper.
We often see a link between Hashimoto’s and gluten. This is called cross-reactivity.
Here is how it works. With leaky gut, partially digested gluten proteins leak into the bloodstream. Your body makes antibodies against them as if they were a foreign invader. But those antibodies can also cross-react with your thyroid tissue. Over time, this damages your thyroid.
So if someone has normal thyroid hormones but elevated antibodies, stopping gluten may be worth trying. The research is not completely settled. But there is a real overlap between celiac disease, non-celiac gluten sensitivity, and autoimmune thyroid disease.
In my practice, I found it worthwhile to have patients avoid gluten for a period of time if they had Hashimoto’s. We would then follow their thyroid antibodies. In many cases, the levels went down.
So here is the question. Has your doctor ever checked your full thyroid panel and antibodies? Or are they just looking at TSH and telling you everything is fine?
If you have had this experience, share your story in the comments below.
Authored by Gerard Guillory, MD
Gerard Guillory, MD, is a board-certified internist who practiced for nearly four decades with a focus on functional, root-cause medicine. He is the author of three books on irritable bowel syndrome and the founder of It’s My Health, where he and his team put current health news in context and help members understand the underlying causes of chronic symptoms.
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