The Thyroid Gland

My Amazing Body is a podcast where we explore interesting, unknown and misunderstood parts of your body with help from medical experts and stories from real Queenslanders.

This episode is all about the thyroid gland. Your thyroid can affect everything from your weight, metabolism, heart rate and brain development – it’s a very important part of your body. Our guest expert Dr Harish Venugopal explains what the thyroid is and the role it plays in your health, and shares tips for keeping your thyroid healthy. He also explains the kinds of conditions –  like hypothyroidism, hyperthyroidism, Hashimoto’s disease, Graves’ disease and thyroid nodules – that can affect thyroid health. We also hear from Queensland woman Leanne about her experience living with Hashimoto’s disease.

Meet our guests

Episode materials

Audio is great, but some things are best seen as well as heard. These materials provide more information about topics we touch on in the show.

A diagram of the thyroid gland

A diagram of the endocrine system

Hyperthyroidism and hypothyroidism

Both hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) can cause serious symptoms. The below diagrams show the symptoms of having an over or underactive thyroid. Dr Venugopal says it's important to remember that not all people will show every symptom.

Support for people with thyroid conditions

Find more information for people living with thyroid conditions at the links below.

Australian Thyroid Foundation

Cancer Council

Episode transcript

Host: Your thyroid is a butterfly-shaped gland that sits at the front of your neck, between your larynx and your collarbone. If you put your chin up in the air a little and stretch out your neck, you might actually be able to feel it with your fingers. Don't poke too hard, it's a sensitive area. Can you feel it there?

That little gland affects everything from your weight, to your heart rate, your brain development and your mood. It might be small, but when it comes to your health, your thyroid packs a mighty punch.

Hi, I'm Elise. Welcome to the latest episode of My Amazing Body, where we explore interesting, unknown and misunderstood parts of your body. Today, we're learning about your thyroid gland. What does the thyroid gland do and how does it work? What causes an overactive or underactive thyroid, and what symptoms should Queenslanders be on the lookout for? Listen on to find out.

Dr Harish Venugopal is an endocrinologist at Gold Coast University Hospital. He regularly sees patients with conditions that affect their thyroid. Dr Venugopal gave us a bit more detail about what the thyroid is and how it works.

Dr Venugopal: The main function of the thyroid is it produces certain hormones, or thyroid hormones as we refer to it as, and the functions of the thyroid hormones are to maintain quite a lot of functions in the body. I think the most important thing is that it kind of regulates energy use, metabolism, it helps with growth development and a lot of other bodily functions like the heart rate and temperature. It's particularly important in childhood and infancy, where it actually promotes brain development and general growth as such.

Host: The thyroid gland is part of the endocrine system, a collection of hormone-producing glands and organs controlled by the pituitary gland in the brain.

Dr Venugopal: First of all, it is an independent organ in itself so it has its own hormones which does its own things, but in the grand scheme of things, most of your endocrine organs are connected by a gland in the brain called the pituitary gland. That secretes a lot of hormones, one of which kind of acts on the thyroid gland and promotes synthesis and secretion of thyroid hormones. In our human body, various hormones do tend to interact with each other, and the general idea is that all these hormones help the body work in a normal way.

Host: Want to know more about other parts of the endocrine system and the hormones in your body? Make sure you listen to episode 3 about the ovaries and episode 9 all about the adrenal glands.

The two main hormones the thyroid produces are called triiodothyronine and thyroxine, or T3 and T4. The body requires a fine balance of these hormones, with too little or too much causing major problems.

Dr Venugopal: Those are the common thyroid hormones that the thyroid produces. If you don't produce enough of that, we refer to that as an underactive state or hypothyroidism. And you do need these thyroid hormones to maintain your metabolism, maintain your energy regulation. And so, the common problems you get when you have an underactive thyroid gland is that you start putting on a lot of weight because you're not metabolising all of that pretty quickly. You can start putting on weight, you can start retaining fluid. People can feel extremely tired. One of the commonest presentations is lethargy.

Sometimes, if it's quite severe enough, it can slow the heart down. It can cause constipation. Sometimes, it can cause confusion.

Host: Dr Venugopal says that because people in Australia tend to be able to seek medical help more quickly than in the past, not every person with hypothyroidism will have all of the symptoms of the condition.

Dr Venugopal: Patients don't classically present with all the features of underactive gland like they used to in the past. One of the other presentations in the past was people presenting comatose because they were so severely underactive and has gone unnoticed for a long period of time. We rarely tend to see those things these days. The commonest presentation I see in my clinical practice is tiredness and weight gain.

Host: While hypothyroidism means your thyroid is underactive, having an overactive thyroid is called hyperthyroidism. Dr Venugopal explains that the symptoms of hyperthyroidism can also be very serious.

Dr Venugopal: When you're overactive, your body goes into a metabolically active state, so it tends to burn more calories, you tend to lose weight which is a common presentation. Feeling very anxious, having palpitations or feeling like your heart racing. In certain types of conditions like Graves' disease, you might also develop some eye problems associated with that which might include pain behind the eyes or double vision.

Host: The thyroid won't usually become over or underactive without cause. Often, an autoimmune condition will stop the thyroid from working properly.

Dr Venugopal: We tend to see several types of autoimmune problems like Graves' disease or Hashimoto's thyroiditis, and autoimmune conditions tend to be the common cause of thyroid problems, not just in Australia but in other western world as well.

Graves' is the commonest cause of an overactive thyroid gland that we see. It's an autoimmune condition and what we have over here is certain types of antibodies that are present in the system that act on the thyroid gland and stimulate the thyroid gland to produce more of the T4 and T3 hormones. And when you have increased T4 and T3, you become overactive and you get all those symptoms that I described earlier on. One of the things about Graves' disease is that these antibodies can also act at the back of your eyes. So, you got very similar receptors at the back of your eyes, so you tend to get a lot of eye problems associated with Graves' disease as well. And we tend to see that the risk of getting eye problem is higher amongst people who smoke. And hence, one of the recommendations when someone has Graves' disease is to stop smoking if they are a smoker, mostly from an eye point of view.

Host: Graves' disease can take a serious toll on the body if not treated.

Dr Venugopal: Most of the patients need some form of treatment to actually fix the Graves' disease. The long-term problems of Graves' disease, if you are overactive, is that it can affect the heart, it can make your heart beat faster, you have a higher risk of going into arrhythmia especially something called atrial fibrillation. It can also affect your bone health and make the bones thinner, a condition we refer to as osteoporosis.

And hence, for those reasons, Graves' disease needs to be treated appropriately. The usual treatment is going with some tablets in the initial instance, but sometimes, you might need a definitive form of treatment to fix the thyroid, which might either include radioactive iodine or surgery. Basically, having the thyroid taken out.

Host: While Graves' disease causes hyperthyroidism, Hashimoto's disease, another autoimmune condition, causes the thyroid to become underactive.

Dr Venugopal: Hashimoto's is very similar to Graves' in terms of the way the condition is come about. So, it's an autoimmune condition where you have antibodies again, but instead of stimulating the thyroid gland like what we see in Graves' disease, these antibodies on the other hand, stop the thyroid from producing the thyroid hormone. So, the commonest presentation for someone with Hashimoto's thyroiditis is with an underactive thyroid gland. With Hashimoto's, again, it's a condition that doesn't go away by itself, and most patients eventually end up becoming underactive and need to go on to thyroxine.

Host: Queensland woman Leanne had returned to work after having her two children when she was diagnosed with Hashimoto's. At first, she put the symptoms down to her busy new life as a working mum.

Leanne: It took a while because I was a new mum, and I went back to work. I had at that stage what would have been a four-year-old and a one year old and I was just going, ‘Oh my goodness, I'm not coping’. I was always tired, I was listless and I just thought it just must be because I'm back at work.

It did take a long time because I just thought this is just normal. This is what other mothers feel. They're just tired, they're drained. I'm just taking on too many jobs. And eventually it was then becoming moodiness like I was just teary at the drop of a hat and that's one of the symptoms. Or I would be very angry, and I would be going to like these extremes of emotion now, either really, really lows or really, really highs. I was fortunate I had a great doctor.

Host: Leanne's diagnosis came as surprise. Autoimmune conditions can be hereditary, but no one else in her family had issues with their thyroid.

Leanne: When she said I've got Hashimoto's disease, I thought oh, my goodness, I am going to die. So, no, I had never heard of it before. No. And no one in our family had had it.

Host: Luckily for Leanne, with proper treatment, Hashimoto's isn't fatal, and can be well managed with medication.

Leanne: I had to go and have an MRI on my thyroid and they found that it wasn't working at all, so then it was a time then of having lots of blood tests and trying to get the medication right.

Host: Leanne's condition hasn't just affected how her thyroid works, it's drastically changed the physical structure of the gland, too.

Leanne: I went to have a scan on my throat recently and the radiographer showed me the image of my thyroid. He said, ‘Look at this moth eaten thyroid!’ Then he showed me his and his was this nice bulging gleaming thyroid and I went wow, it really has, my body has attacked my thyroid and it was quite dull and shrivelled. It looked like moths had eaten it. I thought well, the poor old thyroid, it needed help.

Host: Dr Venugopal says this physical change in the thyroid is expected in someone with hypothyroidism.

Dr Venugopal: When your thyroid becomes underactive, it's not actually producing enough of T4 and T3, it tends to get a little bit atrophied and kind of shrinks and that's pretty much what you would see on an ultrasound in someone with Hashimoto's thyroiditis.

Host: Around 0.5% of Australians have hypothyroidism, and conditions like Hashimoto's affect 10 times more women than men. Even though she'd never heard of Hashimoto's before her diagnosis, Leanne quickly found out that other people she knew were also living with the condition.

Leanne: I was relieved that it was something that – and talking to other people then, I would tell them that I have Hashimoto's disease and I found out that I had another friend that was part of the mother's group and she had it too so we just talked about our journey together and how similar they were and how it also took a long time for them to get the medication right.

Host: Any health condition can feel isolating, especially if you don't know anyone else who's gone through the same thing. We've linked to organisations like The Australian Thyroid Foundation in our shownotes, which provide information and support to people with thyroid conditions.

Now that she's on medication that manages her symptoms, Leanne encourages others to seek help if they're experiencing changes in their body or health.

Leanne: I think sometimes you just have to listen to your body. Well, I had a really good doctor that I could talk to. He said that sometimes people just think it's normal and don't know until they do something about it. He said it's a gradual thing too, so your thyroid is slowly not producing the hormone anymore, so he said it's a more gradual thing that you can't really see until all of a sudden you hit rock bottom.

Host: If you're experiencing any of the symptoms of an over or underactive thyroid, Dr Venugopal says your GP can order a simple blood test to tell if your thyroid is at fault.

Dr Venugopal: I suppose watch out for symptoms of hypothyroidism and overactive gland. And if you do get any of those symptoms, it's better to get it checked out sooner rather than later. The testing is incredibly simple. You just have a simple blood test, a non-fasting, you can have the test on any time of the day. And if that test is normal, then, your thyroid's fine. And that should tell you whether your thyroid's functioning properly or not.

Host: Are you ready for this episode's Mystery Body Part? See if you can guess the body part from the clues given. We'll reveal the answer at the end of the episode.

What am I? I am surrounded by synovial fluid. I allow parts of your body to move and bend. If you pull me apart, I might make a sound that's audible to others.

Besides autoimmune conditions like Hashimoto's and Graves' disease, there are other conditions that can affect the thyroid. Thyroid nodules, thyroiditis and iodine deficiency can all change how the thyroid operates.

Thyroid nodules, or small growths on the thyroid, are quite common, especially as people age. Most of the time they are harmless, but it's important to tell your doctor if you think you can feel a bump on your thyroid.

Dr Venugopal: Most of the time, thyroid nodules don't cause any symptom because they're actually quite tiny and patients don't actually notice it. However, when they have scans – I mean CT scans or ultrasounds – for some other reason, these are kind of picked up incidentally.

Now, the significance of the thyroid nodules is that there is a very tiny chance that it could be cancerous. However, that risk it's actually quite, quite low. And it's quite normal to actually have thyroid nodules. If you were to pick up maybe about 10 people off the street and scan their necks, you'll probably find that three or four them actually have thyroid nodules. It's a very common entity. But theoretically, there is a risk of cancer, which is actually quite small. Nevertheless, there is a risk and when we do identify thyroid nodules, we try and work out whether this could be cancerous or not.

Host: Often triggered by an illness, like a cold or flu, thyroiditis can cause temporary hyperthyroidism. Unlike autoimmune conditions, however, thyroiditis goes away by itself and doesn't require long-term treatment.

Dr Venugopal: Thyroiditis, in general, is a self or a spontaneously resolving condition. We commonly tend to see it in people who have had recent infections. I suppose the common scenario would be someone who would have some form of flu-like illness, and then, subsequent to that, might develop some pain in the neck around the site of the thyroid gland and develop symptoms of, say, an overactive thyroid gland. And when you do a blood test, you realize that they are actually overactive. That usually is secondary to thyroiditis. And thyroiditis basically means that the thyroid gland is inflamed, and when it's inflamed, it just releases some of these preformed thyroid hormones.

And once the inflammation resolves, the thyroid goes back to being normal. Sometimes, people do get an underactive phase after they've been overactive before they can normalise. But it's a self-limiting condition, and it tends to go away by itself. Sometimes, the patients are symptomatic with pain. They might need some painkillers or some anti-inflammatories but generally, most people kind of normalise by itself.

Host: Have you ever wondered why your table salt is iodised? Or, did you even know it was? Very small amounts of the mineral iodine is mixed in with salt to prevent iodine deficiency in the general population. This is important because iodine deficiency can negatively affect the thyroid, even causing goitres, or swelling of the thyroid gland. But Dr Venugopal urges Queenslanders not to rush out and take extra iodine supplements to help their thyroid.

Dr Venugopal: Iodine is an important thing that your thyroid needs, and if you're iodine deficient, you can have thyroid problems. So, that's a definite thing. However, I think the diet in Australia is actually pretty good, you know, the salt that you have, you get iodised salt.

You can get goitres from iodine deficiency. We don't tend to see too much of that in Australia where iodine deficiency is not a very prevalent thing, but in places where I work before like back in India, Nepal where they tend to have significant…just because of the location, and you know, the mountainous region, so you tend to get a lot of patients present with goitres, secondary to iodine deficiency. Over here, I think the main reason you would get a goitre is either because of Graves' disease where the glands just generally enlarged or because you got some form of thyroid nodules.

Our diet is actually replete with iodine, so we don't have to necessarily go and have unnecessary extra iodine supplements on top of that. The problem is if you take too much iodine, it can actually shut down the thyroid. You have some of these paradoxical effects where the iodine kind of shuts your thyroid and makes you underactive. If fact, it's a modality of treatment in people who present with quite severe thyroid toxicosis or overactive thyroid gland and need to have surgery. To bring the levels down rapidly, we actually give them a high dose of iodine.

The iodine does have funny ways of acting on the thyroid. As long as you're having a normal diet, I think that should be pretty fine. I suppose the other myth that we tend to hear a lot about is people taking selenium supplements to try and keep their thyroid good. Again, there's not much evidence on that. Your normal diet, normal healthy diet should have just the normal amounts of selenium to help the thyroid gland.

Host: As always, you should consult your doctor before taking any vitamins or supplements, or changing your diet, especially if you haven't been medically diagnosed with a condition.

Your thyroid is so important to your wellbeing, so how should you look after it? We asked Dr Venugopal what Queenslanders should and shouldn't do when it comes to their thyroid health.

Dr Venugopal: From a thyroid point of view, I think a healthy diet is very important. When I say healthy diet, some of the things I mentioned earlier. Probably having things in moderation and not having excess of anything. So, there are certain things that can actually make your thyroid enlarged in size. So the cabbage classically, cabbage, cauliflower tends to increase the size especially if you have it in large quantities. But if you have it in moderation, that's perfectly fine. A normal diet is all you need to maintain.

And the second thing is to actually, I suppose watch out for symptoms of hypothyroidism and overactive gland. And if you do get any of those symptoms, it's better to get it checked out sooner rather than later. The testing is incredibly simple. You just have a simple blood test, a non-fasting, you can have the test on any time of the day. And if that test is normal, then, your thyroid's fine, and that should tell you whether your thyroid's functioning properly or not. The next thing is about thyroid nodules. If you do notice some lumps or bumps in your neck, get it checked out straight away. Like I said, if it does turn out to be cancer, in the long run, it's quite easily fixable.

Host: Your thyroid's output adjusts throughout your life. Dr Venugopal says that a pregnant woman's thyroid activity might change during pregnancy and will be monitored in their routine blood tests.

Dr Venugopal: The natural course during pregnancy is that women tend to get a little bit overactive, and that's a natural physiological mechanism. And the reason for that is basically, the body needs more of the thyroxine so it can give that thyroxine to the foetus for brain development. So that's the entire concept of becoming slightly overactive during pregnancy is to actually help the foetus with its brain development. But that's just a transient thing and it doesn't kind of generally last throughout the pregnancy.

However, during pregnancy, women do tend to get a lot of other thyroid problems and there's a risk of getting Graves' disease, or even becoming underactive, and that does have its own implications on the pregnancy itself. And hence, identifying a thyroid problem during pregnancy is very important because of the implications not just for the mother, but also, for the foetus or the baby.

Host: Now, if you've listened to this episode and you're convinced you've got a thyroid condition, Dr Venugopal urges you to see your GP to tell them about your symptoms, before you head straight to Dr Google.

Dr Venugopal: I tried Googling myself yesterday, you know, the common thyroid conditions and how do you test for it, and the very first couple of websites that came up were not evidence-based. I suppose that's my concern is that there's lots of stuff on the internet that is actually not based on evidence and it's more of anecdotal about someone who's tried something in the past that seems to have worked and that's now become the fashionable thing, or the ones that people want to do.

I suppose from a thyroid point of view, I think the common things we do tend to see are patients who go on to supplements to actually help their thyroid gland. And again, there's not much evidence from any of these things.

Host: Thanks for listening to this episode of My Amazing Body. Before we go, did you guess this episode's Mystery Body Part? The moving parts of your body surrounded by synovial fluid are, of course, your knuckles! Congratulations if you figured it out.

If you found this episode of My Amazing Body interesting, head over to Apple Podcasts and leave a review to help other people find our podcast. Do you have your own thyroid story to share? We’d love to hear it. Jump on our Facebook page and take part in the conversation.

My Amazing Body is brought to you by Queensland Health. With special thanks to our expert guest Dr Venugopal, Leanne for sharing her story of living with Hashimoto's, the media team at Gold Coast Hospital and Health Service and my podcast colleagues - Lauren our researcher, writer and producer, Carol our audio technician, Dan our music guru and Helen on sound effects.