What’s TSH Normal Range? - Dr. Michael Ruscio, DNM, DC

What’s TSH Normal Range?

Interpreting TSH test results correctly to learn more about your thyroid health

While the Thyroid-Stimulating Hormone (TSH) is just one of the lab markers on a standard thyroid panel, it carries a lot of weight. If it’s interpreted incorrectly, someone may end up on lifelong thyroid medication that they don’t need. In the video, I explain which TSH levels are considered normal and which values truly warrant medication. Watch now to learn the steps to take for better thyroid and overall health.

In This Episode

Intro… 00:08
What’s considered a normal TSH range?… 02:17
The range that may be taking medication unnecessarily… 04:41
Supporting research… 06:32
Helpful resources... 11:56
Exceptions to this rule… 12:35

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Hi, everyone. This is Dr. Michael Ruscio. I just want to make a quick preface that the audio that you’re about to listen to is actually the audio compendium to a video, which has appeared both on our YouTube channel and on our Instagram page for your convenience. We want to always release the audio version of a video here on the podcast. However, it’ll be evident in some videos, more so than others, that the visual aids may be heavily referenced and leaned on. In some cases, having a depiction of a concept can be very helpful in portraying and making comprehendible that concept. So in any case, if you are listening to this and you want the visual aids, please see our YouTube and/or Instagram page so you can have access to those. Okay. And here we go to the audio for today’s video.

➕ Full Podcast Transcript

Intro:

Welcome to Dr. Ruscio radio, providing practical and science-based solutions to feeling your best. To stay up to date on the latest topics, as well as all of our prior episodes, make sure to subscribe in your podcast player. For weekly updates, visit DrRuscio.com. That’s DRRUSCIO.com. The following discussion is for educational purposes only and is not intended to diagnose or treat any disease. Please do not apply any of this information without first speaking with your doctor. Now let’s head to the show.

Dr Ruscio:

Hi, everyone. This is Dr. Michael Ruscio. I just want to make a quick preface that the audio that you’re about to listen to is actually the audio compendium to a video, which has appeared both on our YouTube channel and on our Instagram page for your convenience. We want to always release the audio version of a video here on the podcast. However, it’ll be evident in some videos, more so than others, that the visual aids may be heavily referenced and leaned on. In some cases, having a depiction of a concept can be very helpful in portraying and making comprehendible that concept. So in any case, if you are listening to this and you want the visual aids, please see our YouTube and/or Instagram page so you can have access to those. Okay. And here we go to the audio for today’s video.

Dr Ruscio:

What is a normal range for thyroid stimulating hormone? This is so important because if we get this right, you go on medication that you need, which is lifelong. However, if we get this wrong, one can end up on medication that they don’t need. And shockingly, recent estimates have concluded that 37-61% of people have not gotten the correct perspective on what a normal TSH level is, and therefore have been on medication that they don’t need. So let’s detail this very important concept. This is Dr. Michael Ruscio.

Dr Ruscio:

And let’s start with what TSH level is considered normal as you would see at a Labcorp/Quest/big box lab, and what pretty much all of conventional medicine will agree upon, and this is a range of 0.5-4.5. This is the normative range for thyroid, or for TSH that is. Now if someone is on thyroid hormone, the rules change a little bit. And most of the consensus agree that one should be given progressively more thyroid hormone medication until their TSH hits 2.5 or below. What’s troublesome here is that some in the integrative and functional medicine community have made the conflation that normal, healthy people who are not on hormone should also have a TSH of 2.5. And this is a very fallacious claim, and this is totally discordant with pretty much most of the data as we will outline here in a second. But again, to frame this, most conventional endocrinology bodies and labs will list the normative range for TSH between 0.5-4.5. And this is correct. This is something that conventional medicine really does have correct. When on medication, the goal is to have more medication until your TSH is stable and at/or below 2.5.

Dr Ruscio:

Now here is what gets a lot of people into trouble. It’s this mild elevation of TSH, what’s known as subclinical hypothyroidism. And what I’d like to do is put up on the screen for you as schematically developed to help you better see this because just being above 4.5 does not necessarily mean one is hypothyroid, but it’s important to give outline in the context. So as you’ll see here, above 4.5 is when you are above the normal range for TSH. However, not [everything] above 4.5 carries the same amount of weight. If you’re above 10, there is pretty much unanimous agreement that thyroid hormone would be a good idea. But it’s between this 4.5 up to 7 to 10, that there is debate.

Dr Ruscio:

Now most of the data, and we’ll outline this here in a moment, suggest that people with this mild elevation, this 4.5 between seven to 10, do not require medication, and oftentimes will spontaneously see their TSH go back into the normal range with time when one is getting to above 10. You know, again, that’s when there’s pretty universal agreement. Now also I’ll link to a video we recorded recently that did find simple nutritional supports, namely selenium, and an acetol can help to lower this mildly elevated TSH. Okay. So this is probably the most important concept to wrap your head around, which is if you have a TSH of five of six of seven, the best thing to do is retest in a couple months to see if your TSH, which most do will go back to normal and not to rush onto medication. Now, why is that?

Dr Ruscio:

That is because oftentimes people end up going from doctor to doctor and there’s not enough questioning of was the initial diagnosis of hypothyroid correct. And the assumption that someone should continue on thyroid hormone. And we’ll cover some data later that outlines this, but essentially depending on where you look, as much as 30-60% of people likely went on hormone when they didn’t need to when they had this mild elevation and were able to come off it successfully. So again, above 4.5 is technically high according to the lab range. It’s not until you get to above between 7 and 10 that things could be problematic. So this mild elevation of thyroid or of TSH is known as subclinical hypothyroid. And again, this is what gets a lot of people into trouble.

Dr Ruscio:

So let’s look at the data that supports my earlier statement, that the majority of these cases will spontaneously go back to normal because you can say whatever you want, but show me the data, right? So a 2007 study looking at over 13,000 individuals with a TSH between 5.5 and 10 (remember we discussed this range a moment ago), were followed up at five years and found that 62% had normal TSH levels. So this tells us two things: 1) that over 50% of people will see their TSH go back to normal with time and 2) that we shouldn’t be saying, “well, if it’s a little high now, is it going to get worse later?” Because this was a five-year follow up.

Dr Ruscio:

Now another more recent study, 2021, looked at 225 people who had this mild elevation of TSH. They were given no treatment and 74% had normal TSH at a six-month follow up. So we have two data points here, one longer term (five-year follow up) one shorter term (six-month follow up), both showing between a 60/70% resolution or normalization of this mild elevation of TSH.

Dr Ruscio:

This is why it’s so important not to be too quick to go on thyroid hormone medication. And a 2022 review paper in the Journal of Internal Medicine recommends to repeat a TSH assessment after 2-3 months if you have this mild elevation because most cases where the TSH is between 7-10 or less do not require medication. And to quote the paper here, “overzealous treatment of symptomatic patients with subclinical hypothyroidism may contribute to a dissatisfaction amongst hypothyroid patients as potential hypothyroidism in patients with minimal hypothyroidism rarely responds to treatment. Thyroid hormone prescriptions have increased by 30% in the United States in the last decade. The diagnosis of the subclinical hypothyroidism should be confirmed by repeat thyroid function tests, ideally at least two months later as 62% of elevated TSH levels may revert to normal spontaneously.” Okay. So to continue, generally treatment is not necessary unless the TSH exceeds 7 to 10.

Dr Ruscio:

Okay. So hopefully I’ve convinced you here with multiple data points that if you see a TSH of 5, 6, 7, there’s no need for concern. […] Do be diligent and do have a follow-up test, but don’t jump right onto lifelong thyroid hormone. And if you’re above 10, this is when that probably makes the most sense. Of course, all of these things you want to discuss with your doctor, but I’m just trying to give the information so you can be part of the decision making process along with your clinician.

Dr Ruscio:

Why does this matter? As I alluded to earlier, a recent meta-analysis (which is a study of studies, this is the best representation of what the overall body of evidence is finding) demonstrated 37% were able to come off thyroid hormone and maintain normal TSH levels. And again, why this matters compounded even further, is that these patients did not require lifelong medication and they did not see improvements in their symptoms. In fact, I’ll quote another narrative review, again from the Journal of Internal Medicine, “few patients will experience long-term benefit in their symptoms. And in the elderly aggressive treatment may possibly cause harm.”

Sponsor:

Hi, everyone. If you are in need of help, we have a number of resources for you. “Healthy Gut, Healthy You”, my book and your complete self-help guide to healing your gut. If you’re not a do-it-yourselfer there is the clinic—the Ruscio Institute for Functional Medicine—and our growing clinical and supporting research team will be happy to help you. We do offer monthly support calls for our patients where I answer questions and help them along their path, health coaching support calls every other week, and also we offer health coaching independent of the clinic for those perhaps reading the book and/or looking for guidance with diet, supplementation, etc. There’s also the store that has our Elemental Diet line, our probiotics, and other gut health and health-supportive supplements. And for clinicians, there is our FFMR—the Future of Functional Medicine Review—database which contains case studies from our clinic, research reviews, and practice guidelines. Visit DrRuscio.com/resources to learn more.

Dr Ruscio:

Okay. So we said earlier that the cutoff for when you should start to be concerned is when the TSH goes all the way up to anywhere between 7 and 10, and definitely went above 10. A recent data point from a 2017 study found that the average TSH level, when someone was truly hypothyroid, was 13. So all this evidence showing us that it’s really when you go above 10 that’s when this could be cause for concerne regarding your TSH level.

Dr Ruscio:

Now, as a quick aside, if you’re looking for guidance on how to interpret your lab work, I’ve put a link to our thyroid essentials guide in the description of this video. It’s a free resource that can help give you some of that in writing. You can bring it to your doctor and help make the right decision here so that if you need medication, you get on it, and if you don’t, you make sure to avoid lifelong thyroid hormone medication. And as another resource I’ll link to a recent video we did outlining selenium and myoinositol and their ability via a handful of clinical trials to lower TSH down to the normal when someone has this mild elevation of TSH.

Dr Ruscio:

Now there are a couple exceptions that are very important. In those who are pregnant, and especially in those who have demonstrated a history of infertility, we want to be at 4.5 or below. So that TSH, we should not be as relaxed in our interpretation. And recent consensus guidelines actually are suggesting that in pregnant women, ideally, and especially if they’re pregnant and they’ve demonstrated a history of infertility, the TSH being at 2.5 or below may be optimal.

Dr Ruscio:

Also it’s important to clarify. There is a natural drifting upward of TSH levels as one ages. So if you see this mild elevation, let’s say a 6 in someone who is 16, that’s much different than in someone who is 65. So the younger one is, the more they should be concerned with this mild elevation. So, important to keep that in mind. And this is something you want to discuss with your clinician in terms of your age and your family history as another factor and your symptoms to determine how you interpret that mild elevation of TSH. But remember the older you are, the more natural and normal it is to see a drift upward and the younger you are, your teens, twenties, maybe even thirties, that’s when these things may be more of a prompt to start on thyroid hormone.

Dr Ruscio:

So in summary, remember the conventional ranges, which are accurate. And this is one area where I really think conventional medicine has this right, is 0.5-4.5. An elevated TSH, anywhere between 4.5 up to 7 to 10 is not always a problem. And remember, most of these case—we discussed 60 to 70% of these cases—will become normal with time. So your first step should be a retest in about two months with a caveat and exception in those who are pregnant and/or infertile and those who are young.

Dr Ruscio:

Okay. So this is Dr. Michael Ruscio, and I really hope this helps you navigate this topic because it is definitely a source of confusion for patients and knowing and having good information is a first step in obtaining competent healthcare. And again, I really hope this helps.

 

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