Six thyroid myths debunked by a practicing endocrinologist

What 15 years of treating thyroid patients has taught Dr. Angela Mazza about the misconceptions that delay proper care

Few organs generate as much confusion and misinformation as the thyroid. From social media influencers promoting questionable treatments to well-meaning but misguided diagnostic approaches, thyroid health has become a minefield of myths that can delay proper care for years.

Dr. Angela Mazza has spent 15 years treating thyroid patients and has seen firsthand how these misconceptions keep people stuck in cycles of ineffective treatment. "We were missing a lot of patients with thyroid issues. We weren't treating them correctly, patients were dissatisfied," she reflects on what led her to establish the Metabolic Center for Wellness, where she takes an integrative approach that challenges conventional thyroid paradigms.

With thyroid disorders affecting an estimated 20 million Americans---60% unaware of their condition---separating fact from fiction has never been more critical. Here are the most persistent myths Dr. Mazza encounters in her practice, and why they matter for anyone concerned about their thyroid health.

Myth 1: TSH Is the Only Test That Matters

Perhaps the most damaging myth in thyroid care is the belief that thyroid-stimulating hormone (TSH) tells the complete story. "TSH is really just a screening test," Dr. Mazza explains. "It's an indirect measure of thyroid function."

The pituitary gland produces TSH to signal the thyroid to make hormones. When thyroid hormone levels are low, TSH should rise. When thyroid hormones are adequate, TSH should normalize. But this feedback system doesn't always work as textbooks suggest.

"I'll have people that say, 'Well, my TSH is normal, but I don't feel normal,'" Dr. Mazza notes. "That's where we kind of dig in a little bit more with the circulating levels"---specifically, free T3 and T4, the actual thyroid hormones that do the work in your body.

The clinical reality is more nuanced. Dr. Mazza regularly sees patients with normal TSH but low T3 or T4, or those with underlying Hashimoto's thyroiditis (an autoimmune condition) whose antibodies reveal a progressive disease process that TSH alone would miss.

Myth 2: "Subclinical" Hypothyroidism Means You're Fine

According to Dr. Mazza, the term "subclinical hypothyroidism" represents everything wrong with conventional thyroid care. "I try never to use this term because it means your TSH is a little off... but your T4 and T3 are normal. The clinical part plays no part in the term subclinical hypothyroidism."

This label typically applies when TSH is between 4 and 10, but other thyroid markers appear normal. The problem? It completely ignores how the patient feels.

"It doesn't account for how the person's feeling," Dr. Mazza emphasizes. "It's just a misnomer." This approach often leads to a "wait and see" mentality, leaving patients symptomatic for months or years while their condition potentially progresses.

Myth 3: Thyroid Hormone Replacement Equals Automatic Weight Loss

One of the most frustrating myths for both patients and physicians is the expectation that thyroid treatment will immediately resolve weight issues. "Another misconception is that if your thyroid's off and you're having trouble losing weight, once you start thyroid hormone replacement, you're going to magically lose weight. Well, that's not the case either."

This misconception stems from the simplified understanding that thyroid hormones control metabolism. While true, the relationship between thyroid function and weight is far more complex. Dr. Mazza explains that thyroid problems often intersect with insulin resistance, cortisol dysfunction, and other metabolic issues.

"I try and manage expectations with patients that yes, we want to get your thyroid in balance, but let's look at everything else that's influencing your weight, too," she says. Weight management requires addressing the whole system, not just thyroid levels.

Myth 4: Temperature Monitoring Can Guide Treatment

One dangerous practice Dr. Mazza has encountered is patients trying to self-adjust their thyroid medication based on body temperature readings. This stems from an outdated approach called Wilson's Temperature Syndrome, which suggested that thyroid medication should be increased until body temperature normalized.

"What that ended up doing was making people hyperthyroid," Dr. Mazza explains. Medical professionals have largely abandoned the practice because body temperature is influenced by many factors beyond thyroid function---from infection to stress to time of day. Using it as a treatment guide can lead to dangerous overmedication.

One of Dr. Mazza's patients who attempted this approach ended up in the emergency room. Temperature monitoring might seem logical given the connection between thyroid and metabolism, but it's an unreliable and potentially harmful way to guide treatment decisions.

Myth 5: Levothyroxine (T4) Works for Everyone

Standard treatment for hypothyroidism typically involves levothyroxine, a synthetic version of the T4 hormone. For most people, this works because their bodies can convert T4 into the active form, T3, which regulates metabolism.

But Dr. Mazza's clinical experience reveals a significant gap in this one-size-fits-all approach. About 15% of the population has genetic variations that affect an enzyme called Diodinase 2, which converts T4 to T3. Without this enzyme functioning correctly, these patients can't activate the T4 medication they're taking.

"These people are not going to do well on just levothyroxine," Dr. Mazza notes. For these patients, taking T4 alone is like receiving a medication their body cannot use. They may need combination therapy with T4 and T3, or desiccated thyroid extract that naturally contains both hormones.

Myth 6: Reverse T3 Testing Is Meaningless

Some physicians dismiss reverse T3 (rT3) testing as unnecessary, but Dr. Mazza finds it clinically valuable. Reverse T3 is an inactive form of T3 that can block active T3 from working properly.

"When I was in training, I was told the only time to check reverse T3 is someone who's super sick in the hospital," she recalls. "But we have more and more proof that reverse T3 is legitimate. It gives us a lot of information."

Elevated rT3 can indicate problems at the cellular level, particularly with mitochondrial function, and can help identify patients who aren't responding well to standard T4 therapy.

A More Nuanced Approach

What emerges from Dr. Mazza's clinical experience is the need for personalized thyroid care that considers the whole patient, not just lab values. This includes:

• Comprehensive testing beyond TSH, including free T3, free T4, reverse T3, and thyroid antibodies
• Assessment of micronutrients essential for thyroid function, particularly iodine, selenium, iron, magnesium, and zinc
• Evaluation of cortisol patterns, since adrenal dysfunction can prevent proper thyroid treatment
• Consideration of genetic factors that affect hormone conversion
• Ultrasound evaluation to assess thyroid structure and function

The Path Forward

For patients navigating thyroid health, Dr. Mazza's experience suggests several key principles:

First, don't accept "normal" TSH as the end of the conversation if you're still symptomatic. A complete thyroid panel provides much more information about what's happening in your body.

Second, understand that thyroid health intersects with many other systems. Sleep, stress management, nutrition, and gut health all play crucial roles in thyroid function.

Finally, consider working with physicians who understand the limitations of conventional thyroid testing and treatment. "It's the most personalized medicine there is when it comes to thyroid hormone replacement," Dr. Mazza notes.

The thyroid may be small, but its influence on health is profound. Moving beyond these persistent myths toward more nuanced, individualized care could help millions of patients finally get the treatment they need to feel their best.

This article is based on insights from Dr. Angela Mazza, an integrative endocrinologist with 15 years of clinical experience treating thyroid disorders. Individual medical decisions should always be made in consultation with qualified healthcare providers.

FULL EPISODE TRANSCRIPT

Thyroid test results explained and how the gland shapes health

In this episode of A Whole New Level, Levels editorial director Mike Haney talks with Dr. Angela Mazza, an integrative endocrinologist and founder of the Metabolic Center for Wellness in Austin, Texas. Dr. Mazza specializes in thyroid disorders, including hyperthyroidism, hypothyroidism, thyroid nodules, and thyroid cancer, with a particular focus on combining traditional and functional medicine approaches.

This conversation is part of a series exploring different systems of the body---how to measure their health, how they relate to the rest of the body, and what we can do to keep them functioning optimally. The thyroid is particularly important because it produces hormones that regulate metabolism in every single cell of the body, making it essential for energy, weight management, cardiovascular health, brain function, and overall metabolic health.

They discuss what the thyroid does, how to interpret thyroid blood test results, the difference between hyperthyroidism and hypothyroidism, the role of autoimmune conditions like Graves disease and Hashimoto's thyroiditis, when and how to treat thyroid disorders, and common misconceptions about thyroid health. Dr. Mazza also explains the importance of looking beyond just TSH levels, the role of micronutrients and lifestyle factors, and why personalized medicine is so critical when it comes to thyroid hormone replacement.

What the thyroid does and why it matters

Mike Haney: So the context for this episode is that it's part of a series we're doing around systems of the body and really trying to hone in on a couple of things. How do we measure the health of that system? How does it relate to the rest of the body? And then what can we do to keep it healthy? What can we do to make sure that if we do have a result or something that's out of line that we can bring it back in or just not get an out of range result for that health. So today we're focusing on thyroid. So maybe as a place to start, just tell me a little bit about your background. How did you come to focus on the thyroid?

Dr. Angela Mazza: I didn't start out just focusing on thyroid. I really went into endocrinology because diabetes runs in my family. So endocrinology really is the study of all things hormones. All those countless chemical neurotransmitters that make everything happen in our body. So not just insulin like with type two or type one diabetes, but also thyroid, also our sex steroids like estrogen, progesterone, testosterone. Cortisol is a big one, our stress hormone.

But when I got out of training, the practice I joined, I was the only person that did thyroid ultrasounds and thyroid biopsies. So I naturally got a lot of the thyroid patients. And what I found was one, we were missing a lot of patients with thyroid issues. We weren't treating them correctly, patients were dissatisfied. That's when I started looking at other things like lifestyle, micronutrients, gut health. That brought me to integrative medicine.

And integrative medicine really takes the best of traditional medicine and functional medicine. And that's when I started Metabolic Center for Wellness. And this summer will be our 10-year anniversary. So we take care of persons with all types of hormone issues. A lot of them are thyroid but thyroid overlaps with a lot of other hormone issues because thyroid doesn't just exist in a vacuum. So we take care of hyperthyroidism which is overactive thyroid, hypothyroidism, underactive thyroid, nodules, thyroid cancer. But basically we look at the whole person and I try and work with my patients to figure out how can we get you feeling your best now and years down the line. That's what the end goal is, focusing on resilience and longevity.

Mike Haney: Well, that's a really good place, I think, to get into what the thyroid actually does because you mentioned it does a lot of things and I feel like it's one of those organs everybody's heard of and probably nobody really knows what it does until you have a problem and then you have to learn quickly. So tell me about what the thyroid is doing in our body.

Dr. Angela Mazza: So the thyroid is a pretty important gland because it makes thyroid hormones. So thyroid hormone is our hormone of metabolism. A lot of people think, all right, what is metabolism? I mean, that's the actual question. We think, all right, well, it's what we take in as food and drink and we make energy from it, which it is. That's what the metabolism is. But it's really a lot more than that. Metabolism is all the countless enzyme reactions that are going on in our body at every single point in time. Every single cell of our being is influenced by thyroid hormone. So that's why it's so very important.

And if we don't have our thyroid in balance whether it's too much or too little it can make us feel horrible but it can also lead to complications down the line especially from a cardiometabolic standpoint, bone standpoint, brain standpoint, and countless other reasons why. So that's why the thyroid is important.

Mike Haney: Yeah, it's kind of what the right analogy is, but it sort of drives the rest of the hormones, right? Like as I understand it, the thyroid hormones are essentially signaling to the rest of the body how to control some of the other hormone levels. Is that fair?

Dr. Angela Mazza: Exactly. We sometimes call it the thermostat of our body.

Mike Haney: That's a really good one. Okay. So if we start to see dysfunction in that, it's sort of upstream of then some other dysfunction that might manifest with other systems being off.

Dr. Angela Mazza: Exactly. And the thyroid itself can be influenced by so many other things too that's going on in our body that we don't even think about. So the thyroid is a pretty sensitive little gland. It's super important, but it's important for what it does, which is making thyroid hormone, but it's influenced by so many things.

Hyperthyroidism: When the thyroid is overactive

Mike Haney: So let's talk about what dysfunction looks like. You mentioned hyper and hypo. I think those are the two things people are maybe most familiar with. So hypo being not enough thyroid hormone, hyper being too much. Talk about, let's maybe just start with hyper. What does that look like? How does that manifest in the body? And then what do we do about it if somebody's got hyperthyroidism?

Dr. Angela Mazza: Great question. So hyperthyroidism, sometimes you'll hear the term thyrotoxicosis. In the states here, the most common cause of, and probably across the world, the most common cause of hyperthyroidism is Graves disease, which we can always talk about autoimmune thyroid issues because that's what it is. But what do people feel? Well, think of that hypermetabolic state. So folks usually feel sometimes anxious, trouble sleeping. Some people may feel fatigued. Heart racing. They can have gut issues like loose stools. They can feel shaky. It's not a good feeling at all.

You know, some people we tend to think, okay, if you're hyperthyroid, you're going to lose weight. Not the case because a lot of people actually gain weight when they're hyperthyroid. They may lose muscle. But it's a stressful state that gets us into the effects of cortisol. Cortisol is our stress hormone. And cortisol increases our insulin resistance. So we hold on to all the stores that we have because it's survival mode. So folks with overactive thyroid sometimes experience weight gain.

Mike Haney: Oh that's interesting. Yeah. I could imagine right if you think like oh this is ramping up my metabolism and we all sort of have this picture of fast metabolism equals skinny.

Dr. Angela Mazza: Right. It's a great point that the cascade, I mean to what we were talking about, the impact that it has down the line. So too much thyroid hormone is going to increase cortisol production. And then the cortisol is going to drive that insulin resistance. That insulin resistance is going to make that glucose stay in the system. It's going to make the fat not get burned and you're going to ultimately end up with potentially weight gain. And I'll have folks that say who have hypothyroidism, "Oh, I wish I had hyperthyroidism." No, it's not the case. It's a very, it can be a very disturbing way of living.

I mean people tend to present for evaluation for hyperthyroidism before they present for underactive thyroid because it tends to be very alarming. And folks with hyperthyroidism also may have swelling in their neck, we call that a goiter, that can go along with hyperthyroidism and eye issues. You might see a lot of the commercials on television for thyroid eye disease. That's a very specific type of inflammation within the tissues behind the eyes that cause almost that stare or some people call it bulging. But that can all go along with hyperthyroidism.

Mike Haney: I've read about the eye disease component of this, but I don't really understand the mechanistic relationship. I sort of get that other hormone cascade we were talking about, but how does hyperthyroidism end up affecting the eyes?

Dr. Angela Mazza: So there's really two ways hyperthyroidism can affect the eyes. So there's the sympathetic overdrive that can cause what we call eyelid retraction that goes away very quickly once we bring folks to what we call euthyroid state or normal thyroid state. But there's another autoimmune component that's going on that despite bringing thyroid levels back to normal can keep happening. So it's an autoimmune reaction that causes inflammation in the tissues behind the eyes. And it can be very progressive. It can be anything from just dry eyes or itchy eyes to, in very severe cases, it can cause double vision. It really can impact a person's life where they can't drive. They're bumping into things and in very severe cases it can cause blindness. So that's more of an autoimmune component where it doesn't respond to just bringing a person to a euthyroid state.

The autoimmune triangle: Why some people develop Graves disease

Mike Haney: Okay. And you mentioned Graves disease being the most common cause of hyperthyroidism. That is an autoimmune condition. What do we know about the pathogenesis of this? Why do some people develop Graves and other people don't?

Dr. Angela Mazza: That's a great question. So when we think about autoimmune diseases in general, I always refer to what's called the autoimmune triangle. So there's three points of the triangle. There's genetic predisposition. So I mean, we're born with genes. Some of them get turned on, some of them get turned off, but the ones that get turned on are the problems, especially when it comes to autoimmune thyroid disease.

The second part of the triangle is things we're exposed to over time. Whether it's stress, whether it's environmental toxins, whether it's viruses, medicines we're put on, that kind of is something that we're exposed to along our biography of our thyroid life. And then there's finally the point of even our gut actually plays that third point of the triangle. So those two points of the triangle may be enough to set someone into autoimmune thyroid disease.

But I always try to encourage my patients to say, you know, we can't control the past, but if we can focus on the gut, the gut is something that's very much in our control and we can work to bring it into normal range. Not that it's going to get rid of things sometimes, but it's really a multifactorial process that we develop autoimmune thyroid issues.

Treating hyperthyroidism: Medicine, surgery, or radioactive iodine

Mike Haney: And what does treatment look like? If I come to you and we diagnose hyperthyroidism and we do recognize it's an autoimmune driver of it, how do we manage it?

Dr. Angela Mazza: Great question. And I teach other physicians on managing the initial parts of Graves disease and I always encourage primary care physicians to really partner with an endocrinologist when someone's been recently diagnosed with Graves disease because it can escalate very quickly.

So the initial evaluations once we've confirmed it's Graves disease, what we usually start is something for symptomatic relief. So like that heart racing, that anxiety, usually that's going to be a beta blocker which is a medicine that's usually used for high blood pressure but it really helps calm down the sympathetic overdrive. It'll help people sleep better, help feel more relaxed.

Then we kind of take it from there. There's three routes you can go at this point. So there's medicine. So there's medicine that blocks thyroid hormone production and blocks we call the conversion to active thyroid hormone in the system. There's surgery and then there's radioactive iodine. Me as a physician I try and put surgery and radioactive iodine---so radioactive iodine is treating someone with a dose of iodine that's radioactive. So essentially the thyroid takes up the iodine. In some cases, it shuts down the thyroid function permanently. Sometimes it needs to be treated again. Sometimes it doesn't work.

But surgery and radioactive iodine are things that we can't take back. So once they're there, they're there. So I usually start with the medicine along with symptomatic relief. And as an integrative doctor, I always start our functional treatments. So working on stress management, working on gut health. And we have great antioxidants that really help kind of cool off the thyroid.

So in my experience with Graves disease, and it's been 15 years now, I'm very successful in getting patients off of antithyroid medicines with our integrative therapies. I can tell you in 15 years I've maybe referred two people for surgery and none for radioactive iodine.

Mike Haney: So you do see a pretty good effect size just from managing the lifestyle interventions.

Dr. Angela Mazza: Yes. And since it is autoimmune, sometimes these patients can also have antibodies that go along with Graves, but also Hashimoto thyroiditis, which is the underactive form. So we kind of have to monitor both.

Hypothyroidism: When you don't have enough thyroid hormone

Mike Haney: Oh, interesting. Well, yeah, let's transition into hypo because you mentioned Hashimoto's. What does it look like when I don't have enough thyroid hormone?

Dr. Angela Mazza: It can be gradual in onset. These are more like symptoms that sneak up on us. It can be fatigue over time. It can be a little bit of brain fog, a little bit of mood changes, some gut issues like constipation, joint pains. For women, menstrual irregularities or if they're trying to get pregnant may have trouble getting pregnant. But you may also see things on the labs like cholesterol issues when you never had cholesterol issues before. So it can be very subtle.

I'll tell you one of the things that will drive people to get evaluated for thyroid especially women is if they're having hair changes. So hair loss is a big sign of hypothyroidism and dry skin. And when you start to see something from the external environment then you're like you know what, I better get this checked out.

Mike Haney: Interesting. So those all sound like symptoms that could have lots of different causes. I'm thinking of other conversations I've had with people talking about other systems of the body and I recognize some of those symptoms as well that could be an indication of this. So there's so much overlap. How do you end up diagnosing it? What do you do when somebody comes to you with some of those sort of nondescript symptoms? How do you decide yes, this is in fact hypothyroidism?

Dr. Angela Mazza: Right. So I always take a good clinical symptomatology log, which most hopefully most physicians do. Then I start with the lab testing. So we get the basic labs. TSH, which we can talk about, is a screening test, but you know, I always look at the circulating thyroid levels, which are T4 and T3. I check for thyroid antibodies. So I'm looking for is there an autoimmune thyroid issue that we're missing that may, even though the screening test may be normal, are they actually, is my patient actually having symptoms that go along with this progression of Hashimoto thyroiditis?

That's kind of where I start for screening. I tend to check micronutrients as well. If I'm thinking thyroid, I check for iodine. I check for iron, especially in women. Women, we tend to be low in iron and our thyroid is very reliant upon iron. So if we're not getting enough iron, the thyroid is just not going to work right. So the thyroid is very reliant upon micronutrients. And I do also have the luxury of an ultrasound. So if I'm really thinking something like Hashimoto thyroiditis, I do ultrasounds very regularly.

Understanding TSH and thyroid hormone levels

Mike Haney: Yeah, let's maybe unpack those hormones a little bit and those tests. Because it does relate to the actual sort of diagnostics of this. So yeah, maybe tell me more about TSH. What is thyroid stimulating hormone doing?

Dr. Angela Mazza: Great. So TSH is really an indirect measure of thyroid function. So we have to kind of go back to how is thyroid hormone regulated. So there are very specific parts of our brain, hypothalamus and the pituitary which are constantly sensing what our body's needs are in terms of hormones. When it comes to thyroid, they're sensing circulating thyroid levels.

So if our brain essentially is sensing that we're not making enough thyroid hormone, TSH should go up to say, "Hey thyroid, you need to make more thyroid hormone. Our body needs more thyroid hormone." The same would be true if the brain was sensing we're making too much thyroid hormone, then the TSH should go down. And then once TSH goes up if that's the case then our thyroid should start kind of getting all the machinery together to start making thyroid hormone and that's got many steps involved in that too.

But yeah TSH itself is just an indirect measure of thyroid function. It has a wide range when if you're looking at your labs, if you're at home looking at your labs there, it's a range between 0.4 and 4.5. The debate is, you know, what's normal. As an integrative endocrinologist, I try and shoot for a person's optimal thyroid TSH range, which probably is right around one or two. But what we're finding in genomic studies is there's going to be patients that their optimal TSH may be a little bit higher and their optimal TSH may be a little lower.

And when we're looking at longevity studies that perhaps TSHs should be a little bit higher when we look at centenarians and super centenarians, their TSHs tend to be a little higher. So it's a work in progress on the TSH. But again the take-home point is it's just really a screening test.

Mike Haney: Okay. So I get my TSH and that tells me something. Then what's the relationship I would expect to see then if I get, maybe first explain what a complete thyroid panel is, what else you're testing and then what should I see in those markers or what's the relationship between a TSH reading and the other markers?

Dr. Angela Mazza: Ideally say your TSH is outside of the normal range on the high range. If we check your circulating levels so free T4 and free T3, now I will mention free T4 or T4 is what the thyroid makes mainly. T4 gets released into the body and it gets converted to T3 or free T3. That's really what does the work of the thyroid. T4 is a prohormone, has to be converted to T3. So T3 is what interacts at the level of the cell, that targets the receptors on the respective cell and does the work. That's the workhorse if you will.

So if your TSH is on the high end, ideally we should see a lower or low normal T3 and T4. So meaning that your brain is sensing not enough. When that TSH is high, it means that those levels are low. Okay? So that tells us the system's working basically as it's supposed to in an ideal world.

So if we get a high TSH reading and then we see high markers, high T3 or T4, now that's going to mean something's going on at the level of the brain. Okay. So that's pretty rare. That would be more like a TSH secreting tumor of the pituitary. Very rare. So that's usually not a circumstance that we see. There can be, there's also rare cases of thyroid hormone resistance where TSH may be a little bit high and circulating levels may be in a weird range where it doesn't make sense. That's not the normal situation.

When TSH is normal but something's still wrong

Mike Haney: Yeah. And I know some of the debate out there around thyroid is, well, I have normal TSH levels, but maybe something's still wrong, right? Is that a case we run into? Do we get normal TSH levels, but we still have some symptoms that suggest something to you. So then you go look at T3 and T4 and find things are abnormal.

Dr. Angela Mazza: That's exactly the case. So oftentimes since I'm sometimes someone's second or third opinion when it comes to thyroid, people will say, well, my TSH is normal, but I don't feel normal. So that's where we kind of dig in a little bit more with the circulating levels. I check for the antibodies because the TSH will sometimes, we'll catch it and it looks normal but if you have an underlying evolving Hashimoto thyroiditis because that's a progressive thing, patients may have symptoms. So those antibodies give me a lot of information.

And then there's another factor in there called reverse T3. So as I mentioned T4 gets converted to T3 to be active, but can also convert T4 to reverse T3. The reverse T3 is the inactive form of T3. It looks so similar to free T3 that it can actually block the receptor. So free T3 can't get to the cell and do what it needs. And we see cases of elevated reverse T3 where that's a sign of something else going on. So that's where we have to dig in because that means the body is converting to an inactive form for some reason and that usually points to something going on at the level of the mitochondria which are the powerhouse of the cells. So that's a red flag to me.

Mike Haney: Got it. You brought up reverse T3. It's one of those phrases I see sort of kicked around both as a legit marker and as a don't pay attention to this because it's not sort of real or doesn't or can be sort of misinterpreted. Why is there some debate around the role of reverse T3?

Dr. Angela Mazza: Well, when I was in training, I was told the only time to check reverse T3 is someone who's super sick in the hospital because it could be an evolving, we call it euthyroid sick, which we kind of have fallen out of use of that term. But it's tough to change mindsets when it comes to medicine in general because we're used, even as doctors, we're trained a certain way and it's tough to change the way you're thinking.

But we have more and more proof that reverse T3 is legitimate. It gives us a lot of information especially even if say someone's on thyroid hormone replacement, and we can talk about that, but the standard of care is levothyroxine which is T4. So if someone's on too much T4 we're going to start making too much reverse T3 and that's kind of counterproductive as well. So reverse T3 is a very valid marker because it not only clues us in to what's going on at the level of the cell, but also if you're on treatment, are we mistreating someone with too much T4?

Mike Haney: Interesting. So there is clinical utility of course to looking at those markers.

Dr. Angela Mazza: Yeah. I try and check it in anyone who's on thyroid hormone replacement, too.

What's included in a complete thyroid panel

Mike Haney: Okay. So would that be part of a, we mentioned complete thyroid panel. So I assume that would include T3, T4, cortisol, antibodies. What all is going to be checked if I go to an endocrinologist to get a complete thyroid panel?

Dr. Angela Mazza: Yeah, ideally we should be checking those markers. You bring up cortisol, which is so important because cortisol is really, it's our stress hormone. It's really our most important hormone. We need this hormone to live and cortisol and thyroid go hand in hand. So it's essential to know what's going on at the level of the hypothalamic pituitary adrenal axis as well as the HPT axis. So if we miss something going on at the adrenals it's next to impossible to treat the thyroid correctly. It just won't work.

In addition to the thyroid antibodies. So thyroid antibodies are the thyroglobulin antibodies. So thyroglobulin is really the substance of the thyroid and when we see antibodies against that it means that our immune system is working against our thyroid. And then there's anti-TPO which is anti-thyroid peroxidase antibody. Thyroid peroxidase is really that super important enzyme that's within our thyroid that makes thyroid hormone. That's what iron is really important for. If we don't have enough iron that enzyme can't work but we shouldn't see antibodies to that in our system.

And then we said the reverse T3 and I do check micronutrients because lots of times if I have someone who's just slightly thyroid levels are off, we check the micronutrients like iodine, selenium super important, as I mentioned iron, magnesium, zinc. We replace the micronutrients then the thyroid has what it needs to work and we don't need to put someone on thyroid hormone replacement.

Interpreting your thyroid lab results

Mike Haney: Got it. So what kind of, we talked about some of these other markers. If I'm looking at sort of blood labs that I get back and my TSH is normal, or even if it's not, I guess the question is are there combinations of markers that would reveal something to you or if my TSH levels are normal, but I'm feeling off, I'm having some symptoms that are consistent with potentially a thyroid issue, I should just sort of go see an endocrinologist and let them dig further, or are there really telling patterns that would emerge among this set of markers we're talking about?

Dr. Angela Mazza: Yeah, I mean if things are, if we see a high TSH, low T4, T3, then definitely there's something going on. If you see some like a normal TSH and a little bit low T4, T3, but there's thyroid antibodies, then that's something to get checked out as well. Okay. On the other end of the spectrum, if TSH is low and we see high T3 and maybe high normal T4, that has to be checked out too because that goes along with the hyperthyroidism.

And then there's subtle things and you mentioned there's a lot of overlap with other systems. So I mean that's why it's important to make sure one you get a thorough evaluation even if you suspect you have thyroid issues. As well as make sure we're not missing anything else.

Mike Haney: How durable are thyroid markers? Meaning, if I get it tested today versus next week, how much variation should I expect to see?

Dr. Angela Mazza: That's a great question. And it's going to depend. If you're kind of in your normal stable state and no medicines have been changed or anything, T4 has a half-life of about a week. So just kind of, that means it hangs around in your system for a week. So I mean, that really shouldn't change too much. T3, which is our active thyroid hormone, has a half life of about a day. So that can change fairly regularly based upon the point in time that we're checking.

Now TSH does change a little more slowly. I usually if say I have someone on thyroid hormone replacement, I wait at least six to eight weeks to recheck them again because we want a good steady state with that.

Mike Haney: But if I know with a lot of markers doctors will often say if I get an abnormal result my first thing I do is just retest because it might just be off because it's off for whatever reason. It sounds like the thyroid hormones are going to be a little bit more telling even in that initial reading.

Dr. Angela Mazza: Yes. I mean if you just don't trust the assay that's one thing to recheck. I mean there's no harm in rechecking but if something's abnormal I wouldn't say all right let's check it again in a year. I mean that's not something that I would put off for that long.

Thyroid ultrasound: What imaging reveals

Mike Haney: Right. And you mentioned ultrasound and imaging. When does that come into the picture and what are you learning by imaging the thyroid?

Dr. Angela Mazza: Oh yeah. The ultrasound is really the best way from an imaging standpoint of looking at the thyroid. I mean it's like a real time, no radiation. I see a lot of patients as far as new patients for thyroid nodule biopsies and thyroid nodule ablations. So ablations are a way of non-surgically shrinking thyroid nodules.

So ultrasound serves the purpose of one identifying if there is a nodule. So nodules are like masses within the thyroid, most of them are benign, but depending upon the characteristics of the nodule, we think as far as let's rule this out for cancer. Even though less than 10% of the nodules we biopsy are cancerous, we don't want to miss thyroid cancer.

But thyroid ultrasound can also give an idea of what's going on at the level of the function of the thyroid specifically in autoimmune thyroid issues. So say for example, I have someone who comes in that I suspect Graves disease, but I only have like a low TSH and maybe a weird T3. I'll say let's just, let's not even wait for lab. Just do an ultrasound right now. I'll know what's going on. Help me figure out is it something that's temporary or is it Graves disease? Because I just put the ultrasound down. I can see changes that go along with Graves disease. So we'll see fibrotic changes, sometimes a lot of vascularity.

Now, on the other hand, if I want to say, hey, I think this is Hashimoto thyroiditis, I can see changes on the ultrasound with that. But what that will also tell me is in an ideal situation when I look under the ultrasound it should be this nice ground glass kind of look of the thyroid but if I start seeing changes that look like more permanent changes it'll give me an idea all right are we going to be able to treat this, are we able to one be able to get persons off of thyroid hormone replacement and heal the thyroid or is this something that's a little bit more progressed.

Mike Haney: Interesting. So even in the hyper and hypo conditions, you're actually seeing a physical change to the, is it to the sort of texture or shape of it? Does it get bigger or smaller? What are you actually seeing?

Dr. Angela Mazza: Yeah, that's a great question because it kind of depends upon the point in time where we kind of catch the issue going on. Sometimes we'll just see these especially in Hashimoto thyroiditis because it's kind of an ongoing autoimmune. The immune system is kind of just chipping away at the thyroid itself and that's why it's not working correctly. Because the thyroid is made up of follicles that are constantly making thyroid hormone and when we are attacking these follicles we start seeing little patches within. So that's kind of more mid early on I would have to say.

But it can be the thyroid itself can be enlarged at first because of this inflammation because thyroiditis is an inflammation, anything "itis" is an inflammation. And over time if it's sort of someone who's had Hashimoto thyroiditis for 30 years, we start to see shrinking of the thyroid itself and there can actually be very very little thyroid tissue left.

Thyroid nodules: How common they are and what to do about them

Mike Haney: Right. Interesting. So coming back to nodules, my understanding is they're very common.

Dr. Angela Mazza: Super common.

Mike Haney: That maybe as much as 50, 60% of adults have some nodules on their thyroid. What is the nodule doing? Why do we have a nodule? Like what is it made of?

Dr. Angela Mazza: That is a great question. Well, I always tell my patients, you know, if we ultrasound everybody that walks down the street, about one in three persons is going to show up with some sort of thyroid abnormality on their ultrasound sometime in their life.

Now, the question, there's different types of nodules. So some nodules are mainly liquid. They're cystic. Those are usually never a problem. They can be more of a problem if they continue to fill up with cyst fluid and we have to drain them or do a procedure to ablate them down so they stop filling up. Some are more solid with a little bit of liquid and some are mainly solid.

The question is what causes these thyroid nodules to be there in the first place and we used to think it was abnormalities as far as iodine. So too much or too little iodine, yeah, it can cause thyroid nodules. But what we're finding now is the thyroid since it is influenced by so many things, inflammation is more likely the cause of these nodules. And unfortunately, by the time we know there's a nodule there, perhaps that inflammation isn't there anymore.

So even with COVID, my patients I were following with thyroid nodules, we saw an increase in growth of the nodule after they had infection. So I mean, it's a work in progress on that because we don't, it's tough. You don't know that point in time that triggered the nodule to start growing. But we do know that as far as cancer, I mean, that's in and of itself inflammation does impact thyroid cancer as well.

Mike Haney: Right. So if I've come to you for some kind of a suspected thyroid issue, we've done the imaging and we see nodules. What's the next step?

Dr. Angela Mazza: Depending upon the nodule itself. So there's certain criteria when we look at nodules to determine if hey do we want to do a biopsy. It's based off of size, how it looks under the ultrasound, its vascularity, if it has what's we call microcalcifications, which are little spots of calcium. Then I discuss with the patient, all right, well we need to do a biopsy just to make sure this isn't cancer. Even though, as I mentioned, less than 10% of the nodules we biopsy are cancer, that's kind of the next case.

If we don't biopsy, and this is the first time I'm looking at it, I usually say, "All right, let's take a look at it again in four to six months just to make sure nothing's changed that I can see." Because the ultrasound report that we get, that's a whole other ball game. They're not accurate a lot of the time. And it's not consistent. So I like to be able to monitor consistently.

So whether we biopsy or we observe, and then there's nodules that just really bother people. I mean if they're large nodules, it's on their neck, they can see it. Then we talk about what are ways that we can shrink this nodule for you so it doesn't bother you as much. Because sometimes nodules, they're not only cosmetically bothersome, they can press on your windpipe. They can cause you shortness of breath. They can cause you trouble swallowing. They can press on the nerve that goes to your vocal cords and cause hoarseness. So I mean nodules, even benign nodules can be a problem.

Mike Haney: Right. So the presence, the detection of nodules isn't in and of itself something to freak out or worry about.

Dr. Angela Mazza: Exactly. Yeah.

Thyroid cancer: Slow-growing and treatable

Mike Haney: But then and even if you find a nodule, even if you do a biopsy, is thyroid cancer one of those cancers like a prostate that could be very slow growing that you may not even intervene right away even if the biopsy suggests this might be cancerous?

Dr. Angela Mazza: Yes. 100% yes. So there's four varieties of thyroid cancer. The most common variety is papillary thyroid cancer that grows very very slowly. So say we have a small, we call a micro like a microcarcinoma, so that would be like less than a centimeter that's papillary. Even according to the American Thyroid Association we have options so it can be yes remove half of the thyroid lobe, so that would be go to surgery, that would leave a person with the other half of their thyroid and hopefully that part of the thyroid works well.

We have the option of observation. So that in and of itself causes a little bit of unease with people. So it's saying, well, we know you have cancer. We're just going to look at it every six months to a year. And that can be a very uneasy feeling for a person. I don't know that I would like that.

But now we have radio frequency ablation which is RFA which is a non-surgical treatment. So depending upon that size or where that micro papillary carcinoma is we can actually ablate it and that's an active thing we can do to get rid of it. So we have options now. More aggressive cancers then it depends.

Radio frequency ablation: A non-surgical treatment option

Mike Haney: Yeah, talk more about ablation, that's one of your specialties as I understand. What does that look like? What does that look like if I'm, or what's the feeling, what process do I go through if I'm having something ablated?

Dr. Angela Mazza: Right, so there's a couple different types of ablation. For those cystic nodules that I mentioned, there's something called PEI or percutaneous ethanol injection. Basically, what that is is we take out all the cyst fluid, put in a little dehydrated alcohol that fibroses the inside of the nodule so it doesn't fill up again and you're good to go.

Now, radio frequency ablation, that's better for more complex or heterogeneous or solid nodules. So basically depending upon where that nodule is in the thyroid, RFA is a great treatment that patients themselves are really pushing for. We're trying to educate physicians more because we're stuck in that same mindset. If you have a nodule, the only treatment is if you're going to do something is surgery.

So depending upon the patient, RFA, we do it right in the office. Basically, it takes about 45 minutes. You're numb the whole time. We do keep people awake because we want to monitor their voice because that's something, you know, we want to make sure we're not causing any irritation to the vocal cords or the nerve that goes to the vocal cords.

But basically, the goal is at six months to see a 70% reduction in the thyroid nodule. And it saves people from going for surgery. Because if someone goes for thyroid surgery, we really haven't treated the nodule. We've just removed the whole thyroid. We have a whole other problem. And recreating what a gland does on its own is a lot more complicated than it is because it changes essentially the trajectory of your life from that point on just to get rid of a nodule. So that's kind of the benefit of the RFA.

Life after thyroid surgery: The challenge of replacement therapy

Mike Haney: So if we do end up in that surgery route and we lose part or I understand you could also remove the entire thyroid, right?

Dr. Angela Mazza: Yeah.

Mike Haney: How, what do I do then? What does it look like if I don't have my thyroid?

Dr. Angela Mazza: Right. And that's a challenge that we come up with and I care for a lot of persons that don't have their thyroids anymore, whether it's for thyroid cancer or they had thyroid nodules. It's tough because it's not a one-size-fits-all.

So the standard of care is levothyroxine, which is T4. Now, T4 has to be converted to T3 to be active, which we talked about. There's about 15% of the population that doesn't, they have what we call genetic polymorphisms or gene mutations where that enzyme is called Deiodinase 2. They don't make that. So they can't convert T4 to T3. Whatever they were getting was because of other enzymes that were converting.

So that specific enzyme is important for our brain because we're not going going to be able to convert T4 to T3. These are the persons that are not going to do well on just levothyroxine. And again, we're trying to bring more notoriety about that. There's 15% of the population that you take their thyroids out, they're going to end up with high blood pressure. They're going to gain weight. They're going to develop mood disorders just because they had their thyroid taken out and they're just on T4. And that's where the personalization of thyroid hormone replacement is important.

Combination therapy: T3 and T4 together

Mike Haney: And that leads to what I've seen referred to as combination therapy, right? Where you're doing T3 and T4 together. And what's the, is that only have utility in those cases, in those 15% of people who don't, or are there other cases in which we're finding, because I understand this is relatively new the idea of combination therapy and still maybe a little bit debated. What's the utility of combination therapy?

Dr. Angela Mazza: Actually it's beneficial for a lot of people. And if you think about it kind of we go back to the first thyroid hormone replacement we ever had, something called desiccated thyroid extract. So that came from the original one was bovine thyroid extract. So back in the 1890s, Dr. Murray actually he treated someone, what we call thyroid myxedema. So that's a very severe form of hypothyroidism with this thyroid extract.

So up until, and that's thyroid itself. So it's got all the parts of the thyroid. It's got T4 and T3. So that actually was the original combination therapy. And then fast forward the development of the TSH assay as well as levothyroxine. At that point the tide shifted to shifting everybody over to levothyroxine, following mainly just the TSH.

That's where we started having the emergence of patients with persistent hypothyroid symptoms and people that just weren't getting better on T4. Now the pendulum's swinging back again. We're looking at our complete thyroid panel. Some people need that extra T3 whether it's in the form of levothyroxine plus liothyronine which is T3 together or a desiccated thyroid extract like would be like Armour Thyroid or NP Thyroid. Those are kind of the brand names.

The role of other systems in thyroid health

Mike Haney: Okay. So it sounds like particularly when we get to the even at the diagnostic stage and particularly at the treatment stage, it sounds like there's a lot of individuality that comes into play here and that's just due to our bodies being different or is it interacting with other systems? In other words, if I have something else off in me, if I have type two diabetes and I have a thyroid issue, does that point you in a different treatment direction?

Dr. Angela Mazza: Yes, it's actually I think the most personalized medicine there is when it comes to thyroid hormone replacement. But you are correct. It's going to be influenced by our other systems like our adrenal status, inflammation in general. Women, perimenopause and menopause is a huge one because changes that happen with our estrogen and progesterone as we age, and perimenopause starts in a woman's early 40s. For some people, it's late 30s and it's all the way through menopause, which is just a point in time.

But that at least 10-year block is, it's changing thyroid function too and it's affecting if a woman's on thyroid hormone replacement or if she's evolving into having a Hashimoto thyroiditis. That's one thing that we see a lot of.

Common thyroid myths and misconceptions

Mike Haney: One of the areas I want to make sure we have time to cover here is misinformation or maybe confusion to be sort of less malign about it. But thyroid is one of those things that gets talked about a lot more than I think other organs on social media, among influencers, among maybe folks who aren't qualified or just people who have good faith debate about some of these diagnostic criteria, some of these treatment plans. Maybe I'll just start here. What is some of the most persistent things you see out there that folks come to you with that they've heard or they've read somewhere or somebody's told them that you have to kind of correct or knock down? What are some of the most common myths or misunderstandings about thyroid health?

Dr. Angela Mazza: One that I've seen is if you're on thyroid hormone replacement, kind of dates back to just following temperature. So that we advance thyroid hormone replacement until temperatures normalize. That actually has fallen to the side. That was at one point was called Wilson's temperature syndrome. Because what that ended up doing was making people hyperthyroid. I have one patient who was doing that on their own and ended up in the ER. So it's not a good route to go. I mean, we want to use clinical along with the labs because that's what we have them for.

Another misconception is if your thyroid's off and you're having trouble losing weight, once you start thyroid hormone replacement, you're going to magically lose weight. Well, that's not the case either. Again, thyroid is affected by so many things. Insulin resistance in and of itself is affected by so many things. So I try and manage expectations with patients that yes, we want to get your thyroid in balance, but let's look at everything else that's influencing your weight, too, because just putting someone on thyroid hormone replacement, you're not going to lose like 20 pounds overnight. That's kind of the big one.

And managing expectations is probably a big one because there's just no overnight change. I mean even when thyroid hormone is perfect, we still have to continue to address the other factors that are going on. Lifestyle is huge, stress is huge, sleep is huge, gut health is huge.

Unpacking "subclinical hypothyroidism"

Mike Haney: Right. I mean the phrase you see a lot is subclinical hypothyroidism, right? Which maybe you can unpack that. What do people mean when they say subclinical?

Dr. Angela Mazza: Right. I try never to use this term subclinical because it means that one, your TSH is a little off and the range, as we say, a TSH between like four and 10, but your T4 and T3 are normal. The clinical part plays no part in the term subclinical hypothyroidism. It's just not a criteria. It's just a term we use where we say, "All right, the TSH is off, but if you check those other levels, they're normal. That means that end of game, we just recheck it again in six months." But it doesn't take any account of how the person's feeling. So it's just a misnomer.

Mike Haney: So I mean, it strikes me that one of the ways that this can sort of confuse people is because these markers can vary a lot because they intersect with a lot of symptoms that can be multifactorial, could have lots of different causes. I mean, do you get a lot of folks coming to you saying, you know, look, I have some fatigue. I feel a little off. We could squint and look at these markers and say, if we use subclinical, they're a little off. I just want to go on a little bit of hormone replacement therapy. What's the, why shouldn't I just try that to see if it's going to help?

Dr. Angela Mazza: Now, there's nothing wrong with doing that. I mean, if someone if we think, all right, well, maybe we could make this a little bit, maybe this T3 a little more optimized. There's nothing wrong in doing that. I mean, especially if a physician is going to follow up and recheck levels and re-evaluate symptoms. But that's where I would also say it might be this, but we need to check your adrenal axis. We need to know what's going on there because that sometimes that's the real issue.

I just did an online master class where we included a cortisol curve in all these patients that were considering they were having thyroid symptoms. All the cortisol curves were off. So if we don't fix the adrenal axis, you're never going to feel better just tweaking thyroid hormone up and down.

Mike Haney: Yeah. Yeah. So and is there, you mentioned it probably can't hurt as long as you're being guided, but what's the risk? What would you argue against somebody diving into the treatment plan of thyroid hormone replacement?

Dr. Angela Mazza: Yeah, you might have side effects. I mean, side effects of too much thyroid hormone, especially if you don't need it, are palpitations, anxiety, sleep problems, you just might not feel better in general. You might have some hair changes. So it's not a quick fix. So that's where I have the conversation. I mean, we can try it, but we need to look at other things, too.

Mike Haney: And is that a reason that you might start with sort of lifestyle things first and say how much of these symptoms that you're having, which could be caused by a lot of different things, can be addressed with some of these lifestyle changes before we go down the road of getting you on this?

Dr. Angela Mazza: Yeah. And I should mention the micronutrients are important too. So I mean if we replace the micronutrients that may be absent, then the levels if they level off then that kind of takes the abnormality out of the picture as far as the thyroid hormone. So yeah I mean it's a, I look at patient care as a team. I present all the options. We come up with a consensus what we want to do, but I try and give all of the options because I don't want to lead someone down the path that all your symptoms are thyroid when they aren't.

Can you get off thyroid hormone replacement?

Mike Haney: Right. And if I start on replacement hormone, can I get off of it at some point or am I committing to a life of doing this?

Dr. Angela Mazza: That's a great question because actually we are successful in getting patients off of thyroid hormone replacement. Just because you're on thyroid hormone does not mean that it's this is what you're going to have for the rest of your life. It, as long as you have a thyroid and we're able to optimize your own thyroid function, you don't have to be on thyroid hormone replacement or less thyroid hormone anyway. So it's especially in the case of Hashimoto thyroiditis because I use those thyroid antibodies as a guide to what's going on with the immune system.

If we address what's going on with the immune system, it allows the thyroid time to work for itself a little bit and then we can get patients on less and some patients depending upon how much they required to start with, none at all.

Mike Haney: Interesting. So you can sort of regain normal thyroid function.

Dr. Angela Mazza: Oh yeah. It all depends upon going back to the ultrasound. If I see the antibodies go down but it also depends upon what it looks like. So if it looks like, hey, this is, I hate to say end of the spectrum, sort of the chances are low, right?

Lifestyle factors to keep your thyroid healthy

Mike Haney: But so let's maybe end with what folks can do with maybe the preventative care side of this. What can they do to make sure they don't have to come see you? You know, yeah, some of these things we talked about autoimmune conditions, something like Graves, maybe there's less you can do to kind of prevent that. But in terms of just keeping your thyroid healthy, we've been talking about a lot about lifestyle and micronutrients, but maybe dive into specifics. What lifestyle factors do you like folks to do and what micronutrients are important to keep healthy levels of to just make sure your thyroid is as good as it can be?

Dr. Angela Mazza: Great question. So in order to prevent coming to see me, so the goal is from a lifestyle standpoint, sleep is so essential. We live in a 24-hour society where nobody shuts down. But try and get sleep. Sleep is essential. I mean, seven to nine hours of sleep is important.

Stress management. Because cortisol curves should be highest first thing in the morning with a gradual decline towards the end of the day and it shouldn't be high all day long. It shouldn't be low all day long because that's going to impact thyroid function too. So if we can stay ahead of stress, again, that's a tough one. I mean, everybody's under stress, but trying to at least manage what you can and don't make managing stress become stressful. That's tough, too.

Detoxification on a regular basis is so important because we're exposed to countless chemicals on a regular basis between the food we eat, the things we clean our house with, the things we clean ourselves with, medical products. We're exposed to endocrine disruptors all over the place. We can't get away from that. Again, don't let that be stressful. I always say to my patients, but if we can help our body handle it a little bit better. So detoxifying, getting antioxidants in on a regular basis.

Selenium is a super important one to help protect your thyroid. Selenium is essential to not only help the thyroid work, but it protects the thyroid from inflammation. So making sure, it's as easy as two Brazil nuts a day getting selenium, a little bit of pumpkin seeds. That's all you need as far as selenium and the thyroid needs. So sweating every day helps us detoxify. It doesn't have to be a sauna. Doesn't have to be a 10-day detox or anything. Just simple things that help our body detoxify. Hydration is important.

Trying to stay away from foods that are overprocessed. That's essential. I mean, trying to get whole organic foods as much as possible. Those are kind of the key things and that probably echoes a lot what you hear from other folks as far as hormones. So it's the more we keep our body in balance, the more we decrease inflammation, it kind of protects our thyroid now, preserves our health now, and when you're looking down the line, not needing to see an endocrinologist, but preserving our longevity and resilience as well.

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