When it comes down to it, you are likely wondering what all your thyroid labs might mean and what they signify for your health.

Today, I am going to do a deep dive to break all of that down for you. To leave you with a clearer picture for your health. Especially when it comes to explaining the causes (and the ways we test) abnormal thyroid levels.

I definitely understand when things can be frustrating because they are important to your health, they are coming off as unclear.

Maybe they were not explained very well by your doctor. Or, perhaps the explanation simply did not make sense.

Was it hypothyroidism? Hashimoto’s? Graves’ disease? What is going on in your body, and what can you do to understand it and fix it? I want to go through all these super important tests with you.

Together, we can make total sense of them to better benefit your long-term health.

A Helpful Tool

As part of this article, I wanted to gift you with a handy tool that can help you make sense of your lab results.

This handy calculator is exactly what you need. All you need to do is enter your results to receive great personalized feedback.

You will learn:

  • Some of the most likely diagnoses
  • The action steps you should be taking
  • How to get the help you need along the way

Bottom Line: I am super excited to share this with you. So that you can get a clearer picture of your health and what you can do about it. You can find the calculator by Clicking This Link.

The Important Markers

As we dive into each of these tests, I am going to give you a clear understanding of how to interpret them. Let’s begin with one test that I am almost positive you have heard me mention before…


Those who have been following along for a while now will be no stranger to the importance of TSH. This is your thyroid stimulating hormone, TSH for short. It is essentially your brain telling your thyroid to get to work.

The TSH works by getting the thyroid to grow additional cells. The more underactive your thyroid, the higher the TSH goes. On the other hand, if your thyroid is overactive your TSH goes lower to help slow things down.

Key Insight: The thyroid only works when it is told to work. So, when the TSH goes up, it is “yelled at” and it works harder. Otherwise, it simply slows down and doesn’t do much. But that’s okay because that is how our bodies keep things regulated.

So, what happens in various disease states with your TSH?

Simply put, we define hypothyroidism and hyperthyroidism based on TSH levels. If your TSH is clearly above 10 or more, that is what we know as overt hypothyroidism.

In between 4.5 and 10, this is where the T4 becomes important and is what we know as subclinical hypothyroidism (Read: Learn the truth about subclinical hypothyroidism today).

What To Do With Your TSH?

This is definitely not me saying that everything is fine as long as your TSH is not high. You can certainly have hypothyroid symptoms, even if your TSH is lower than 10. That said, we define hypothyroid based on the TSH.

When the TSH is low, this is when we are talking about hyperthyroidism. If the TSH is below 0.4 – 0.1, this is what we call subclinical hyperthyroidism (if the free hormones have not elevated).

If you are all the way down to 0.001, then it is defined as hyperthyroidism (Read: Should you ignore your TSH).

Key Insight: The main cause of hyperthyroidism is what we know as Graves Disease. This is an autoimmune attack that causes the thyroid to release too much hormone. The main cause of hypothyroidism is what we call Hashimoto’s thyroiditis.

Many folks have been told that they are hypothyroid, but they do not have Hashimoto’s. The truth is that cases of this happening are pretty unusual. Yypically only occurs secondary to surgeries to remove the thyroid or medications that slow it down.

Bottom Line: Many that have Hashimoto’s do not have measurable thyroid antibodies. If you are hypothyroid, you likely have Hashimoto’s disease (unless there is some other cause like the ones that I have detailed above).

Special Circumstances

When it comes to your TSH, there are some special circumstances worth considering. If it is a question of hyperthyroidism, it is important to know that your TSH can run lower during pregnancy.

Free Hormones

Now we need to start thinking about the hormones that the gland releases. The gland works by taking a protein, thyroglobulin, and places iodine atoms onto that. Creating two things:

When it is released as T4, it leaves the thyroid and becomes T3 (wherein the T4 “loses” one iodine and goes from 4 to 3).

Both T4 and T3 are measurable. Your body releases some of both – a lot of T4 and a little of T3 (with most T3 being made outside of the thyroid).

Measuring these free hormones comes in two different ways, there is:

  1. Total T4 and total T3
  2. Free T4 (fT4) and Free T3 (fT3)

Key Insight: If it doesn’t explicitly say “free” or “total,” then it is safe to assume that it is the total.

What’s the Difference?

The difference is that these hormones have an active chemical state. A lot of them can be bound up by carrier proteins (which results in them being inactive). The total is combined active and inactive, whereas free is merely the active fraction.

For most people, if you know the total you know about how much free hormone that they have. That said, there are some cases where you have enough total with the free being too low (or vice versa).

Bottom Line: This leads to a general understanding that free hormones are preferable to total hormones. Free hormones, though, only reflect hyper and hypothyroidism at their extremes. They do not reflect subtle changes, and they are usually the last marker to change in a disease state.

Thyroid Antibodies

This is the next big category that I want to tackle. Of the thyroid antibodies,1 we have:

  • Thyroperoxidase
  • Thyroglobulin
  • Thyroid Stimulating Immunoglobulin
  • Thyroid Receptor Antibodies

We will dive into each and every one of these to help give you a better understanding of each.


This one has the most significant overlap with Hashimoto’s disease. Most people with it do have high levels of anti-thyroperoxidase, but not all (in fact, many do not).

The labs will call a small amount normal (if you are below 32, you will be told that it is normal).

But, to a certain degree, it still stands as an attack on your thyroid! Or, it can be a sign of other problems or autoimmune responses potentially wreaking havoc on your body. High Thyroperoxidase overlaps with instances of:

  • Rheumatoid Arthritis
  • Type 1 Diabetes
  • Celiac Disease

Key Insight: Thyroperoxidase, when it is really high, can play an important role in predicting fertility risks. Apart from fertility, though, these antibodies are not known to affect health in other ways.


Less consistently specific with Hashimoto’s, thyroglobulin does still have overlap with arthritis, diabetes, and celiac disease.

Both thyroglobulin and thyroperoxidase are present in Graves’ disease. In fact, up to half of the people with Graves’ disease may have anti-thyroglobulin.

Anti-Thyroid Stimulating Immunoglobulin

Thyroid stimulating immunoglobulin, or TSI for short, is an easy thing to think about: TSI is just about TSH, and that is kind of how it works in the body, too.

We can think of TSI as an unhealthy signal. It goes from your immune system telling your thyroid to release hormone.

When there is too much thyroid hormone, your brain shuts off TSH trying to slow down your thyroid. But, your TSI can continue making your thyroid work (even if your body is trying to stop it).

TSI is present in 90% of patients with Graves’ disease. About 10% of the time it can be present in those that have Hashimoto’s disease.

When TSI is high, it can pose a great risk for Graves’ disease – but it can also pose a risk for Graves’ eye disease (and Graves’ dermopathy, a skin disorder).

That is why, in this case, it does help to keep TSI down to help control other non-thyroid negative health outcomes.

Anti-Thyroid Receptor Antibodies

This is a variation of TSI that is important to know about. In fact, it is pretty much the same thing, but it is not as good of a predictor as TSI. Over half of those with Graves’ disease will not have high levels of thyroid receptor antibodies.

It does not have non-thyroid effects, so the jury is out on whether it has any other effects apart from being closely related to TSI. It is also not commonly tested for, because it is less predictive.


So, now that we covered the antibodies, let’s touch on thyroglobulin. Antithyroglobulin is the attack on the protein that forms the thyroid hormone. Thyroglobulin, though, is just the protein itself and nothing more.

Some of it is normal in the bloodstream, and it is proportionate to the rate of thyroid cell death.

Thyroid cells wear out, die, and new ones take their place – so the rate at which they are dying is the amount of thyroglobulin in the bloodstream.

Thyroglobulin is most useful to determine what someone’s risk would be for thyroid cancer or a recurrence of thyroid cancer.

The data is at its best when someone has had thyroid cancer, and they had high thyroglobulin before they went on treatment.

Key Insight: In cases like those, you can measure thyroglobulin to see if their cancer came back. Apart from cancer, thyroglobulin can be high in cases of goiter, nodules, or even with Graves’ disease.

The last thing is that if someone has ultrasound findings that are ambiguous, thyroglobulin can act as a tiebreaker between biopsy and surgery.

When high, it can spell future problems. When low, it can show that you have more breathing room than you think.

Reverse T3

I am covering reverse T3 last for a reason, and that is because I do not really test for it. Reverse T3 is the normal byproduct of T4, and many have argued that reverse T3 blocks the effect of T3 in the body.

This has been thoroughly studied in all animal species and it does not. Instead, we should think of the concept of “reverse T3” as the mirror image of T3 – so it is effectively the same thing, in a different shape that would not work in the other’s receptor.

Why do we even have it, then? This is just another example of just how powerful thyroid hormones can be in the body – and how many ways the body has to regulate them properly.

When things work well, your thyroid is in a state of spitting out a lot of T4. Your liver, in charge of the fine tuning, takes this T4 and makes enough T3. Mostly, though, it makes reverse T3 – a byproduct that the body will never need.

What if Reverse T3 is High?

If the reverse T3 is high, it means that there is simply too much thyroid hormone (and that someone is either making too much, taking too much, or their body is unable to tolerate it at its current levels).

Key Insight: There are no cases where reverse T3 is high, that it is high by accident. The most common scenario, by far, is someone simply taking too much thyroid hormone. In cases like these, we either need to lower the dose or however much the thyroid is making

Reverse T3, most of the time, ends up being a test that costs patients money and insurance does not want to pay for. Another scenario worth considering is where the body cannot tolerate thyroid hormone.

This is called euthyroid sick syndrome, and it is most commonly seen in Intensive Care Units (ICUs) in hospitals.

In cases like these, the body is intentionally slowing down to maintain the right metabolism for someone who is not stable – and the solution is not to take more T3, because the body does not want it.

Bottom Line: As is often the case, the solution is not simply to take more of something that is not benefitting your body at all. Instead, we need to focus on root causes and managing where symptoms are coming from (treating the disease instead of simply managing it).

How To Best Understand Thyroid Markers

Your thyroid markers are so important to your overall health, and the kind of treatment options you should be pursuing.

That is why I am so excited to have made this Thyroid Calculator for you, Click Here, to help give you a clearer picture of your health and what you can do with numbers that might seem a bit confusing at first glance.

Now you can plug in all your numbers, find out what they mean, and make the right choices for your long-term health moving forward.

I hope that you will give it a chance and that you can get on the road to feeling better starting today.


1 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5422478/

P.S. Whenever you are ready, here is how I can help you now:

1. Schedule a Thyroid Second Opinion with me, Dr. C, Click Here for Details
2. Download and use my Favorite Recipes Cookbook Here
3. Check out my podcast Medical Myths, Legends, and Fairytales Here

Dr. Alan Glen Christianson (Dr. C) is a Naturopathic Endocrinologist and the author of The NY Times bestselling Adrenal Reset Diet, The Metabolism Reset Diet and The Thyroid Reset Diet.

Dr. C’s gift for figuring out what really works has helped hundreds of thousands of people reverse thyroid disease, lose weight, diabetes, and regain energy. Learn more about the surprising story that started his quest.