Did Your Doctor Say Your Thyroid Is Fine? (Three Reasons for a Missed Diagnosis)

“Your labs look fine!”

My patients share this nearly famous quote from their primary care providers all the time. That’s how they end up in my office, of course. Because they’re not fine. They feel terrible, with their hair falling out, gaining weight for no reason, freezing all the time, debilitating fatigue, brain fog. They look and act like a walking, breathing hypothyroidism textbook and yet…their other doctors say they’re “normal.”

What gives?

As a functional medicine doctor, thyroid disease is one of the main problems I treat in my office. While some patients walk in already knowing they have a problem and what it is (they’re looking to slow progression of their condition, or treat it without prescription medication), the majority have never gotten a diagnosis to finally explain their symptoms and start treating them at the root cause.

Why do thyroid problems so frequently go undiagnosed?

In my experience, there are typically three (categories of) reasons that my patients fail to receive an accurate diagnosis for their symptoms when they see other doctors. These are the three reasons that they might get told they’re fine when, in reality, they are struggling with thyroid disease. They might be told it’s in their head or (gasp!) probably perimenopause because, as if they didn’t realize it already, “You’re in your 40’s now…”

In my opinion, making an accurate diagnosis is not hard. Sure, the years of schooling that teach healthcare providers how to screen for all these different conditions and what they mean can be very challenging indeed. But, once you know the information, you just need to do the thing.

So, without further ado, here are the three reasons that my patients receive a misdiagnosis or have a missed diagnosis of a thyroid condition:

1. They’re not running comprehensive enough tests

This might sound obvious, but if you don’t test your thyroid you’re never going to accurately confirm a thyroid problem.

Unfortunately, most doctors don’t actually test thyroid function on screening labs. Sure, they run Thyroid-Stimulating Hormone (TSH) but fail to acknowledge that TSH does not actually test thyroid function.

TSH is a hormone the brain makes to tell the thyroid what to do. The thyroid is then, in turn, supposed to produce T3 and T4, which are the main thyroid hormones. The liver is supposed to make proteins called thyroid-binding globulins to carry these hormones through the blood stream to tissues, acting as a reservoir for these important hormones. The tissues themselves (gut, liver) are supposed to conver T4 into T3 as needed, per-diem to run metabolic functions in cells.

All of these functions are testable. Yet, most healthcare providers don’t test them.

Why?

They fail to recognize that TSH isn’t the full picture. Our brains are smart, but they’re even smarter than we give them credit for. Meaning, on account of other cellular processes going on in the body, the brain might be perfectly fine with an underfunctioning thyroid, thank-you-very-much, and carry on its normative signaling despite underfunctioning of our main metabolic regulator.

If you don’t test the full thyroid panel, you don’t get the full information. And if you don’t have full information, you can’t rightfully rule in, or out, a thyroid condition.

There are seven different main patterns for hypothyroidism, and I explain them all in my post titled: The Root Cause of Hypothyroidism. Check if out if you are curious what might be going on behind the scenes.

If you aren’t working with a functional medicine doctor, I’d encourage you to ask your PCP to run the full list of tests for you.

2. They don’t test frequently enough

You don’t need a medical degree to know that our metabolic needs when we’re sleeping differ dramatically form when we’re running a marathon. We also have different metabolic needs when we are resting versus when we are stressed. Our thyroid needs likewise differ when we’re sick, when we’re tired, when it’s winter versus summer, and according to the menstrual cycle. In fact, TSH levels on blood work even differ throughout the day! (They’re typically highest in the morning.)

If you’re concerned you have hypothyroidism, your doctor is going to be looking for an elevated TSH level. Remember that TSH is thyroid-stimulating hormone, meaning it’s released in order to stimulate the thyroid’s production of thyroid hormone. If the thyroid is under functioning, the brain will send a stronger and stronger signal to get the thyroid to pick up the pace, akin to an angry boss yelling at a lazy employee.

In many cases of hypothyroidism, the deficiency is subtle, with the TSH level only sometimes exceeding the reference range, typically only in the morning when TSH levels are highest. (That is, not to mention, that many labs and subseqently, many physicians, use a reference range that is far too broad; but that’s a different post for a different time.)

So, if you only test TSH (which most physicians do) and only test it once per year (which is the current standard “screen”) and don’t remind patients to remain off biotin supplements (which many physicians forget about) and don’t require a morning, fasted draw (which most don’t) then there is a good chance you will miss the elevated TSH level and your doctor will wrongly tell you that your thyroid is “normal” when it ism in fact, not.

But of course, you knew that, because your symptoms and intuition are hard to ignore.

3. They forget about the immune system

The most common cause of hypothyroidism is an autoimmune condition called Hashimoto’s Disease. But, here’s the thing: you can have Hashimoto’s and not yet have hypothyroidism.

Hashimoto’s as an autoimmune disease means that a person’s immune system is wrongly attacking their thyroid. The immune system is supposed to produce antibodies aimed at fighting off infections, like COVID or Epstein-Barr virus, or strep throat. But, with Hashimoto’s, the immune system instead starts making antibodies against thyroid tissue, called anti-thyroperoxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies.

The result is thyroid inflammation and evnetual thyroid tissue destruction, accompanied by all the immune symptoms that make you feel sick, like fatigue, brain fog, joint pain, hair loss, depression and…do I sound like I’m describing hypothyoridism yet?

Remember that TSH does not screen for Hashimoto’s Disease, yet Hashimoto’s Disease is the number one cause of hypothyroidism. Also keep in mind that while Hashimoto’s Disease often leads to destruction of the thyroid gland and eventual resulting hypothyoridism, it doesn’t always; but it still produces symptoms of its own accord that notoriously accompany hypothyroidism. Because of these symptoms, Hashimoto’s sufferers often feel too unwell to exercise, or eat well and likewise gain weight just as they would with full blown Hashimoto’s hypothyroidism.

Maybe you’ve already been tested for Hashimoto’s and told you don’t have it, but your symptoms are so suspicious that you’re not sure you believe the diagnosis. Of course, it’s possible that you don’t have Hashimoto’s or other thyroid disease, and you need to keep advocating for yourself and digging to find that answer.

But then again, remember this: most people with Hashimoto’s weren’t born with it. Rather, they were born with a genetic predisposition that was triggered by something, such as Epstein-Barr virus, COVID, gluten sensitivity, or, notoriously, hormonal and immune shifts such as those seen in puberty, pregnancy, postpartum and perimenopause. This means that even if you were previously tested for Hashimoto’s and the result was negative, that may have changed at some point throughout your life. My own doctor even incorrectly told me that if the antibodies are negative, they’re negative and there’s no point in retesting. I’m grateful that I had the knowledge to advocate for myself and get the appropriate lab work.

I want that for you, too.

So, friends, remember that you are the one who knows your health best. If something feels off, it definitely is; it’s just a matter of testing for it. (And that means running the right tests, running them frequently enough, and remembering to be comprehensive!)

I hope this helps you to get the best posible healthcare. You deserve it!