I had a request to do an updated thyroid testing video, like what's in a proper thyroid panel and why do we do it and what do the numbers mean? So I'm kind of going to just go through the list. Name the test. What are the normal ranges for us, the functional normal ranges, why do we do it? What does it mean? How does it interact with the other tests? So if you have a thyroid panel either from me or from somebody else and you want to pull it up and go through it while I do the video, hopefully it'll help things make sense for you. But I think I've done these in the past. Someone was having trouble finding one, so they asked me to do an updated version. Here it is. So when you do a thyroid panel, the lab mixes it up and presents it in different chunks.

(00:48)
So I'm going to go through it in the order in which your body makes and processes thyroid hormone from asking for it in the beginning, all the way to active thyroid hormone at the end of this. So you may have to move around in your report a little bit, but you'll find these if they're in there, first of all, TSH or thyroid stimulating hormone that comes from the pituitary, which is a little gland kind of, if I could touch my fingers together there kind of tucked up under the front of the brain and that pituitary, it also tells your ovaries or testes your adrenals, your pancreas. It tells those what to do as well and your thyroid. So it makes TSH to specifically tell the thyroid how much T four to produce T four is the main thyroid hormone produced by the thyroid. We'll get to that in a second.

(01:43)
So TSH is the pituitary telling the thyroid what to do. It's not made by the thyroid and it only kind of indicates whether the thyroid is doing its job or not. But there's a certain amount that we expect somewhere between one and three, I would consider pretty normal lower than one is normal in some cases, as long as the thyroid is making it a hormone in response to it, then it's fine. The idea is or was that if you weren't making enough T four, the TSH levels would start to climb. You'd be asking for more and more and more over time, and if you made a lot of T four or took T four, then the TSH would go down dramatically and you'd quit asking for any production because you're getting what you need orally or your thyroid's just doing its own, making a ton of it anyway.

(02:33)
So that's the relationship that's supposed to be there about half the time, especially with autoimmune cases. That relationship is not intact. It's what I call the TSH is what I call uncoupled from the T four. It doesn't track inversely like that. I have patients where we can look at several reports in a given period of time and their T four can be perfectly stable and their TSH is all over the place. That's an issue. We're aware of it. It happens a fair amount, like I said, a lot of times in autoimmune cases. But what that means is that trying to use the TSH as a way to make medication decisions, I think is a huge mistake. I think you should actually be looking at the T four and the T three, not the TSH. I put it on all my panels because it's kind of the language that the medical industry uses when they talk about thyroid, and if we can prove that you're uncoupled that we shouldn't be paying attention to it, why not?

(03:36)
Now you can take that to your other doctor and say, look, this is not the number you should be following. So anyway, that's TSH. So TSH tells the thyroid to make T four. Now T four is tyrosine, which is an amino acid part of the proteins that we eat with four iodine molecules attached to it. So T four is tyrosine four iodine molecules. That's the thyroid hormone that comes out of the thyroid. There's a little bit of T three, but we'll get to that. T four is the main product that the thyroid makes. Now, T four isn't active. It's a packaged form of thyroid hormone. You can't use it in that form. You have to process it and turn it into something more usable on down the road. This is more to be shipped out to different parts of your body. So you'll have two numbers for T four.

(04:26)
You will have a total T four, which should be between six and 12. That's what we expect to see from a functional perspective. Now, most labs will go all the way down to four or maybe four and a half. I think that's generally way too low for people. 12 is generally the upper limit. Sometimes you see 12.5, but T four, my opinion should be kind of between six and 12. Now you don't feel much of that, right? That's just available to be activated later on. Most of that is going to be bound to protein in the blood and kind of rendered useless at that point. But a small amount of it is not bound to any protein in the blood, and that's what we call free T four. T four is also called thyroxin. I should probably mention that your lab may say thyroxin and then T four.

(05:16)
So free T four is the part that's available to go on to the next step and become active thyroid hormone, that number should be between one and 1.5. Now to me, especially on the upper end, there's a little wiggle room on that. If you were 1.6 or 1.65, I don't know that I would really care. I'm looking to get to the final product here, but it's important that that be included in the process. That number, the free T four, and I'll explain to you why in just a minute, but that should be between one and one and a half, 1.5, and that's the free T four. Now that goes into the liver predominantly, a little bit of this happens in the intestines. They say about 60% of this conversion happens in the liver, maybe 25 or 30% in the intestines, and then you get 10 or 15% scattered randomly throughout cells in the body where they kind of convert this on site.

(06:10)
But the conversion we're looking for is to have an enzyme that's called five prime de-iodinase. It's an enzyme that removes one of the iodines. So you go from T four to T three because you lost one of the iodines, but that opens up a receptor site and makes it more active and more able to interact with your cells. That's an oversimplification, but it's a good way to think of it. Now I'm just going to talk about the liver. So coming out of the liver, you had one to 1.5 going in the liver. That was the free T four, one of the iodines gets removed, and then you have T three coming out of the liver. We expect that total T three number to be somewhere between 101 80. That's a good range. Now again, the labs go down lower than that, but 100 to 180 is a good functional range of that.

(07:07)
Again, most of it's going to be bound to protein in the blood. A small amount of it's available to actually interact with your cells. That's free. T three, and that's what this whole thing was about was producing free T three. That number should be between three and about four, maybe four and a half on the upper end. That's the range you're looking at for free. T three, if it gets much above that, sometimes you get symptoms of being anxious and jittery and keyed up and hot and sweaty and can't sleep. That's over caffeinated would be the best way I could probably describe that feeling. I haven't had it, but I have plenty of patients Talk to me about it on the low side, if it's below three, you end up with thinning hair, weak nails, cold hands, dry skin, constipation, weight gain, poor libido, brain fog, inflammation.

(08:02)
Those things go along with not having enough active thyroid hormone. But here's the deal, the free T three range, even my functional range goes from three to about four and a half. I'm convinced there are people whose bodies are kind of set where they're happy around 3.3 or 3.4. That's their sweet spot. Well, if that person's at 3.0 2.9, they're probably going to feel fine, but if their set spot is 4.1 or 4.2 and they're sitting at 2.8 or 2.9, they're going to feel like trash. So that normal range, you can have a spot in that normal range where you all of a sudden feel great and then other spots where you don't feel so good. So it's not just like as long as you're in the range, you're fine. If you're in the range but still have symptoms, then maybe you need to be shifted up or down in the range and see if you feel better at a particular narrower piece of that range.

(09:03)
So that's the free T three. Now, the relationship between free T four and free T three, sometimes we have people for whom the free T four number is 1.5. They're at the top end of the range going into the liver for that conversion. But when we look at total T three coming out, they're at a hundred or they're at 90, they're at the bottom end of the range. That's a mismatch. We would prefer you be in the same third of the range the whole way through, right? Let's say your total T four number six to 12 is normal. You're sitting at seven, you're at 1.4 for free, T four going into the liver right upper end, but not topped out on the range. You come out of the liver with a total T three of one 50, right middle to upper end of the range, and then your free T three is three and a half.

(09:58)
Well into the range. That kind of matches all the way through. When we start seeing like your T four levels are up at the top of the range and your T three levels are down to the bottom of the range, you're starting to have an issue with conversion, right? You're making plenty, the thyroid's fine, but you're not able to convert it to the active form, so you still feel pretty trashy, right? Eventually that split will go far enough that T three drops out of the normal range. Now you've got a mid or upper level normal range for T four, and you're below normal for T three, a hundred percent a conversion issue at that point. Is it liver? Is it intestines? Debatable, but that's a conversion issue versus someone where the total T four level is five, right below the range, six to 12 is normal.

(10:49)
The free T four level is say 0.7, right? So below that one to one and a half total, T three is 60 and free. T three is 2.3, right? Everything is below the range. That's a production issue in the thyroid, get the T four level up, there's a good chance the rest of the cascade just moves right up with it. That's different than someone who's making plenty of T four and then it drops off when they convert to T three. So there are different things that can be going on that if you're seeing each step of the process, you're able to get a better sense of where the breakdown is. If all you see is T, s, H, you know nothing at that point. If you see TSH free T four, free T three, okay, you've got some information, but there are binding proteins involved.

(11:45)
Sometimes you make a good amount of total T three, but you have so many binding proteins because of your inflammation that you're binding it all up and there's very little free T three available. You wouldn't know that if you're not getting both. Okay? So those are some of the nuances. Now, we also have reverse T three, and then we have the antibodies reverse T three. The easiest way I can describe it again, an oversimplification. It's a particular mistake that the liver makes where instead of removing this iodine, you remove this iodine and it makes a mirror image of T three, reverse T three, and that's not terribly usable. You pretty much have to throw that away. And so sometimes when we see a low T three, we see a conversion issue. Sometimes that reverse T three will be elevated, and we get a sense that there's definitely a mistake happening in the liver.

(12:42)
Now, I'm going to make some people upset here, some other functional medicine docs, so feel free to leave comments, but I'm going to try to be fair here. Many doctors will tell you that the reverse T three is a mechanism your body can use to kind of feather the brakes a little bit or hit the gas a little bit. If you don't have enough thyroid hormone, it's going to lower that reverse T three low enough that you can make use of everything, right? It's going to try to open up the floodgates and let you have absolutely every bit of T three you can, and if you have too much thyroid hormone, you may raise the reverse T three as a way to kind of feather down those active hormone levels. I've seen plenty of people where that relationship is not shown in the lab work, right? They're not using reverse T three as a way as a last ditch effort to kind of manipulate that free T three number.

(13:48)
It is low because there's not enough hormone. It's high because there's lots of hormone. I don't see it being used intentionally like that. Now, I've done a lot of these hormone panels. I've read a lot of these hormone panels. Maybe I'm just misinterpreting it, but I haven't seen enough evidence that our body is using that purposefully to try to manipulate the system. So I'm not on board with that. I don't think that's the way it happens. I think it's a mistake in the processing and the healthier the liver is, the less burden it is by toxins. The better quality processing you're having, the lower that reverse T three number is likely to be, in my opinion. Now, antibodies, TPO antibodies are the main ones we want to look at. That's what's going to get you diagnosed with Hashimoto's, most likely. The general range for that.

(14:38)
Anything above, I mean, anything that shows up, you're capable of making the antibodies, right? It's probably irrelevant, but you're capable of making them. If the level gets up above the thirties, like 35, 38, 40, 45, something up in that range, now you've turned positive on the lab test. You have Hashimoto's, you qualify for the diagnosis, you have an autoimmune thyroid problem, all of that. But when we go to the treatment side of this, if we can get those TPO antibody levels down below 200, according to most of the research, you've kind of slowed down the damage enough that it's not that relevant. Like it's calm enough that you could almost call it remission functionally, at least to have levels below 200. Some people say 150, but still it's in that range. So the 35 at which you get diagnosed, you could have a TPO level sitting A TPO antibody level sitting at 45 for years.

(15:37)
You're probably not doing any noticeable damage. Do you have Hashimoto's? Yes. Is it resulting in low thyroid hormone? Probably not. But if your levels are five or 600, you are doing significant damage. You're causing problems for the way the thyroid functions. The TPO antibodies are attacking the TPO enzyme, which is in the thyroid, assembling your iodine and your tyrosine to make that T four. So if you damage that enzyme enough, you can't assemble the T four and your T four levels go down. So that's possible. The thyroglobulin antibodies are attacking something different. They have a whole different threshold. We don't want to see it much above one. To me, that doesn't necessarily get you a Hashimoto's diagnosis, although for a lot of doctors, they will. To me, I just use it as a sign. The higher the number, the more active your autoimmunity is, the lower the number, the more we've managed to throw a wet blanket on that fire and calm it down. So it is targeting proteins that shuttle thyroid hormone around the body. So it's not really a production issue. It's more of a transport issue, and that's harder to see on your hormone levels in your lab work. So I'm not saying it's less relevant, but it's more difficult to connect the dots of the relevance on your lab work. So we look at it, it's a general indicator of autoimmunity in the thyroid, but that's kind of how I use it.

(17:07)
So that's your full thyroid panel. Those are the numbers and the ranges we're looking for, and a little bit about what it means when those numbers are out of range. So next time you go to your family doctor, gynecologist, endocrinologist, and you're getting a thyroid panel, see if they'll do a full panel for you, even if they don't think it's all that relevant, you now have a way to go assess that and kind of judge the relevancy of that. And then if you see something you don't understand, come to the office, let us know, and then we'll help you kind of try to figure out where the autoimmunity is coming from or is there a nutrient missing that's keeping your thyroid from being able to do its job. We will kind of do some troubleshooting and see what we can figure out to get rid of the underlying problem so that your thyroid hormone cascade can work the way it's supposed to.

(17:59)
It's not about treating the thyroid or giving you hormone. It's about looking at where the problems are, figuring out what normally is required for that piece of the puzzle to work, and then making sure that you have that in place and that we're not doing something that's going to get in the way of that function and letting the system work the way it's supposed to, right? Trying to get down to the root cause and trying to just get roadblocks out of the way and let that production system work the way it's supposed to. So hopefully that helps you out. If you have more questions, let me know. I can certainly do a revision video on this, but it's been several years. Obviously, it's time for me to do a new one of these. So hopefully that helped you out. Hope you have a great afternoon and we'll see you later.