An endocrinologist explains the function of the small and mighty thyroid, common thyroid disorders, and how to support thyroid health.
Over 20 million Americans have some kind of thyroid issue – and 12 million of them don't even know it. Dr. Hyesoo Lowe joins Faith to explain what the small and mighty thyroid does — from regulating our body temperature, to supporting heart function, digestion, even energy and mood. They discuss why thyroid issues impact women more than men, what to do to support thyroid health, and explore the signs that might mean it’s time to head to your doctor to look into your thyroid function.
Welcome to Health Matters, your weekly dose of the latest in health and wellness from NewYork-Presbyterian. I'm Faith Salie.
If you've been feeling tired, a little down, maybe waking up puffy? ...Yes, these common symptoms can happen to any of us on an off day, but they are also associated with a thyroid disorder.
This week, I talked with Dr. Hyesoo Lowe, an endocrinologist and a thyroid specialist at NewYork-Presbyterian and Columbia, who explains what the small and mighty thyroid does — from regulating our body temperature, to supporting heart function, digestion, even energy and mood.
By some estimates over 20 million Americans have some kind of thyroid issue – and 12 million of them don't even know it. Listen to my conversation with Dr. Lowe to get a handle on how your thyroid is working hard for you—and how to tell if something's off.
Faith: Dr. Hyesoo Lo, thank you so much for joining us.
Dr. Lowe: Happy to be here. Thanks for having me.
Faith: I'm very excited to learn about the thyroid because to me it seems small and mighty and a little mysterious. So, can you please explain where it is, what it looks like, and what it does?
Dr. Lowe: The thyroid gland is definitely small and mighty. Although it's one of the largest endocrine glands that produce hormones. And it's a butterfly shaped gland. It sits right in the lower central neck. And most of the time people are unaware of their thyroid gland. You can't really feel it. There's a layer of muscle that's right over on top of it, sort of holding it in place. But in general, the thyroid is quietly doing its work underneath the surface for all your life. In specific terms, the two thyroid hormones made by the thyroid are T4 and T3. And in predominance, more than 90 percent of what the thyroid produces is T4. And the main, job of thyroid hormone is to sort of be an assisting hormone. It assists in a variety of body processes. These are things like maintaining your core, body temperature, maintaining your metabolic rate and how you burn calories. It contributes to cardiac function, digestive function, even parts of energy and mood.
Faith: That’s very crucial assistance, I’d say.
Dr. Lowe: Indeed it is. So then when there’s a problem with the thyroid, which the most common issue is a functional problem where the thyroid slows down and becomes a bit underactive, Generally it's sort of a gradual process. But the most common issue is something called Hashimoto's. And we assign that name because that's the doctor who discovered the idea that an autoimmune attack on the thyroid cells can lead to to a condition of underactive thyroid.
And what happens is your immune system, which is doing its normal work, which is to make antibodies so that you can recruit your immune system to fight and defend you against illness, right? So you're making antibodies to things you've been vaccinated against flu, COVID, um, things like this. Um, and that's fine, but some people just make for no good reason, extra antibodies and these extra antibodies are able to then turn in and start fighting against you, instead of defending you. And depending on the focus of those autoimmune antibodies, well, that will sort of determine which autoimmune condition you have, and it just so happens that the most common autoimmune antibody you can make are those directed against the thyroid. So it is really the most common cause of hypothyroidism is this autoimmune process.
Faith: So we've started describing some disorders. I saw some statistics that an estimated 20 million Americans have some form of thyroid disease and up to 60 percent of those with thyroid disease are unaware of their condition. So, will you share with us some of the symptoms?
Dr. Lowe: Yeah, of course. So there are two types of problems with the thyroid. Number one is, is it functioning normally or no? Is it hypo active? Meaning do you have under active thyroid or do you have overactive thyroid hyperthyroidism? The symptoms will be opposite. And so we'll go through those.
And then the other type of problem you can have with the thyroid is you can have a nodule or a lump. And whenever we think about a nodule or a lump anywhere in the body, really, you want to know, well, is this a benign thing that I can live with? Or is there a chance this is dangerous? Could it be a cancer? And do we need to act accordingly?
So those are the two types of things that we deal with. So let's start with hypothyroidism, the most common thing. Um, unfortunately, some of the symptoms that go along with hypothyroidism are extremely non specific. In other words, if I went out in the street and I asked everybody if they had these symptoms, many, many people would raise their hands to the symptoms of waking fatigue, swelling and puffiness around the face, around the hands and feet, constipation, cold intolerance, maybe a little bit of low mood or depressed mood. A lot of people have these symptoms.
Faith: Yeah.
Dr. Lowe: Um, but those are all indicative of the general slowdown of the body processes that may happen as the thyroid slows down. And so when those overlap with the proper blood testing that can confirm, um, that those symptoms are due to thyroid, um, those are the things to look out for.
uh, infertility and recurrent miscarriage is another thing to think about. Some people will discover their thyroid disease as a result of the evaluation of those problems and maybe had no symptoms whatsoever, but come to find out they're having a thyroid issue and that is leading, um, to the consequences of potential difficulty in achieving pregnancy or even miscarriage down the road.
Some people who are otherwise healthy may have no symptoms at all. They, um, their body just sort of handles, um, sort of as a mild thyroid under activity and you sort of can move about life in this way for a number of years,
Faith: So you've just characterized the most common thyroid disorder. It is hypothyroidism. And, uh, here I will reveal that I was diagnosed with hypothyroidism, oh, 31 years ago. So I'm going to deduce that the symptoms of an overactive thyroid, hyperthyroidism are, um, okay, I really listened. So they would be running hot. Right? Feeling, having extra energy?
Dr. Lowe: You got it. So if you have hyperthyroidism, you kind of feel like you're on a, a speeding train. And so that metabolic rate is high, you're losing weight.
And actually, whether it's in response to that or just a general direct response to, um, elevated thyroid hormone, people feel really hungry. So some people just are eating much more than they normally would. And despite that, they're surprised to see that they've lost weight. But you're absolutely right. People will generally run hot physically in their temperature. They may complain of night sweats or just sort of sweats during the day. Rapid or frequent bowel movements is another one. So people feel like whatever they eat is going right through them. Insomnia, anxiety, palpitations those are the most common things that would come to attention. And so you can see those are a little bit more dramatic and more noticeable to a patient, especially palpitations. So, um, I'll get a patient once in a while who's really physically fit and they'll say, you know what, I went on my normal run, uh, and, For some reason I had to stop earlier. I had to stop for breath and I never have to do that. And I realized my pulse was just really racing very fast. And so those are things that come to attention a lot sooner because people will notice.
Faith: I think there's good news here. Are, aren't both these conditions treated quite easily?
Dr. Lowe: We can replace these thyroid hormones, for the most part, with a pill, with a medication. And that medication is actually the identical biochemically identical version of the thyroid hormone that you were making to begin with. So hypothyroidism, if you're missing a certain degree of thyroid hormone, well, we can fill up the tank with a pill that is the same thyroid hormone your thyroid was making.
Now, hyperthyroidism is a little bit different because in that case we're trying to control or suppress an excess amount of thyroid hormone, and so that requires a different type of medication that gets to the thyroid cell directly in order to stop or decrease the actual production of thyroid hormones. So that's sort of a different concept altogether, but again, uh, also very treatable.
Faith: What would happen if someone with either of these conditions was left , undiagnosed and untreated?
Dr. Lowe: In the case of hypothyroidism, these body processes that slow down first would cause a bit of discomfort, right? So patients would get symptomatic and they would have all those symptoms that we talked about. But over time, um, and every once in a while we'll see something like, like this, where a patient hasn't seen a doctor for 50 years and they come into the hospital and they've got fluid around the lungs, fluid around the heart, some of the most feared complications of hypothyroidism where the body is unable to properly handle body fluids.
In hyperthyroidism, um, the, body processes are going too fast. And so one of the most dangerous parts of that is the heart is actually over stimulated. And one problem with that is it could be stimulated to an arrhythmia and something like atrial fibrillation or a flutter. These are actually relatively common arrhythmias that can happen with or without thyroid disease, but certainly can be exacerbated or even caused by hyperthyroidism.
Faith: You've explained the two most common thyroid disorders, which are hypothyroidism and hyperthyroidism. And then there is a, uh, meaningful other type of thyroid disorder or disease
Dr. Lowe: Yes, so Thyroid nodules are actually incredibly common. In autopsy series, it has been found in up to 50 percent of people that a thyroid may contain a nodule so they're very common for some reason the thyroid is tissue gets sticky, um, maybe over a person's lifetime and it just can lend itself to forming a lump. The good news is that most of the time they're not cancer. About 90 percent benign and 10 percent of them may be thyroid cancer that need to be dealt with. So, um, many times, People have no idea they have thyroid nodules. As I said, you can't even feel your thyroid, let alone something that is deeply embedded inside your thyroid. But a lot of times people will find a nodule. Incidentally, they're getting a CAT scan of something else for a different reason altogether. They're getting an ultrasound of their carotids to make sure that they have no blockages in there. Um, many times people will incidentally have that outside finding of a by the way, There is also a thyroid nodule present and you should get that evaluated.
Faith: why are women five to eight times more likely than men to have thyroid problems? I read that one woman in eight will develop a thyroid disorder in her lifetime.
Dr. Lowe: Many thyroid disorders are autoimmune conditions. Well, it just so happens that women develop autoimmune conditions at a much, much higher rate than men. Why would this be? This is a great mystery. Nobody's quite sure about that.
Faith: Are there certain ages when, where the thyroid needs more support?
Dr. Lowe: Yes, there are. And it starts. in utero. So the thyroid needs maximal support from mom in the early stages of the first trimester. So proper amounts of thyroid, maternal thyroid hormone are necessary to support fetal brain development. And so this is why it's so important that, patients who have known hypothyroidism are in really good shape in terms of having enough thyroid hormone and having normal levels of thyroid hormone before they get pregnant. Thyroid cancers may increase in size during pregnancy. So these are things that sometimes we need to be monitoring, um, especially if there's a known problem ahead of time.
Faith: I've always heard a connection between iodine and thyroid health.
Dr. Lowe: So iodine is the backbone of thyroid hormone. In fact, the thyroid cell itself has to pick up iodine that gets pumped into the, into the thyroid cell, use that iodine and turn that into thyroid hormone. So iodine is extremely important and that's where T four comes in, there are four iodines on T four, and then in T three, these are the thyroid hormones. There are three iodines. So you see we need iodine in order to make thyroid hormone. And just like many things in life, we need just enough. Not too much. Not too little. We need just enough.
And so, uh, it's important to know the sources of iodine. In the United States, we have regular old table salt that is iodized. And then there's a variety of non iodized salt, fancy salts that people use, um, you know, in cooking. These are actually non iodized and actually, as salty as junk food and packaged foods are, those are usually not made with iodized salt. Other sources of iodine are things that come from the sea, seaweed, which is very popular as a snack, sushi, um, all shellfish, seafood, fish. Regular fish. Those are all excellent sources of iodine. Vitamins are fortified with iodine in many cases, prenatal vitamins for sure. Um, so these are all important to know.
Faith: it sounds like the best thing to do in any of these cases is go talk to your doctor and get your blood tested.
Dr. Lowe: You are exactly right.
Faith: Dr. Lo, just like a healthy functioning thyroid, you are mighty and, um, and of great assistance. So thank you so much for explaining all this today.
Dr. Lowe: It is my pleasure.
Our thanks to Dr. Lowe.
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Faith: Dr. Lowe, this is making me hold my head. First of all, I'm having feelings about my pink Himalayan sea salt. It's betraying me. if If anyone's like me, I'm thinking, oh gosh, we're supposed to cut down on sodium. But does my sodium have enough iodine? And am I having maybe too much iodine or not enough? It's a lot.
Dr. Lowe: A half to one teaspoon a day of regular old iodized table salt is all you need. Um, and many people are getting it anyway with their outside iodine sources from food. So not to worry. The Himalayan sea salt is okay with me.
Faith: Okay, thanks. It's so pretty.
Dr. Lowe: It's gorgeous.