Thyroid Function Test

Essential Thyroid Labs



Sound Familiar?

Skeptical business woman

“I’m tired and depressed, and I’m starting to gain weight. I think it’s my thyroid, but my doc says my labs are normal and I’m fine. No, I’m not fine! Something is wrong, and I need answers!”


“My friend’s doctor tested her thyroid with seven or eight different tests, but mine only tested my TSH, total T3 and total T4.
Do I need more testing?”

woman think

“If I don’t run the right tests, could I have hypothyroidism and not know it?

Where do I start? How do I know what I REALLY need?!”

It’s not in your head. Hypothyroidism is REAL.

And it’s not at all uncommon for people, usually women, to go years or even decades with a hypothyroid condition and not know it.

Usually they’ve been to see their doctor as well as specialists—multiple times. They’re told that their “labs are normal” and they’re “fine.”

But they are NOT fine!

For one, they probably had insufficient tests run. Or they had their tests improperly interpreted. Or both.

There is so much variety in the ways doctors run thyroid labs, in fact, that a person can get a different set of tests and interpretations from each practitioner they see!


The big problem is that most doctors run only one test, measuring your level of TSH, or thyroid-stimulating hormone. Others may run a total T3 or total T4 too, but as we’ll see, those tests alone are not adequate to truly assess the state of your thyroid.

What’s more, there is serious disagreement over what the normal values are in a TSH test.

Put that all together, and you have a lot of “normal” lab results for people who are clearly suffering from low thyroid—or hypothyroidism as it’s known in the health world.

Given all the confusion around thyroid testing, how do you know what’s right for you? Never fear! We’re going to show you, simply and clearly, what you need to know when it comes to thyroid labs, so you can get a true picture of your thyroid’s health and—if you are hypothyroid—get your life back quickly and naturally!

If you suffer hypothyroid symptoms—whether you’re on thyroid medication or not—and your doctor is telling you you’re fine, we urge you to read the following information.

Let’s get to it! First of all, as we’ve said, simply running a TSH measurement will NOT tell you whether you have a hypothyroid condition. We repeat, a TSH test alone is not sufficient!

So What Exactly is TSH?

TSH stands for thyroid stimulating hormone. It’s produced by your pituitary gland, which sends the hormone to your thyroid as a way of telling the thyroid to produce more thyroid hormone. That is, TSH is not a thyroid hormone. Instead, it’s the hormone that kicks your thyroid into action.

Generally speaking, the more TSH you have in your blood, the louder your body is crying out, “More thyroid hormone, please!” An abnormally high TSH level indicates that the thyroid gland is failing to do its job—a condition known as primary hypothyroidism. (Primary hypothyroidism, by the way, is just one of the eight major types of hypothyroidism.)

Can You Have a Normal TSH Level and
Still Have Primary Hypothyroidism?

Yes better believe it! One reason for this is that there are many opinions as to what a normal TSH value really is. When you get a THS test done, you will get a result back with a “reference range” printed near the TSH measurement. This is the range of values the lab that ran your test considers normal. It is also known as the “acceptable” reference range.

In the opinion of Traditional Medicine, the acceptable reference range for TSH goes as high as 4.0 or even 5.0. Yet our experience shows that this upper limit is far too high! Many individuals with a TSH level above 1.5, in fact, show classic signs and symptoms of hypothyroidism, and most people feel their best between 0.4 and 2.0.

While many doctors will go solely by the acceptable reference range in assessing the state of your thyroid, we at Yuvalabs prefer to evaluate TSH results according to the “optimal” reference range. This range corresponds to TSH values exhibited by people who aren’t just free of hypothyroidism symptoms but show clear signs of optimal thyroid function, such as good energy, stable mood and healthy metabolism.

We highly recommend you make the optimal reference range your standard. Why? Because we know you not only want to only eliminate the symptoms you’re struggling with—especially the exhaustion, depression, mood swings and weight gain—you want to feel vibrant, energized and full of life! You want an optimal thyroid!!

You need to have your doctor run other tests beyond a measurement of your TSH level. This is important. Without these other tests, which we describe below, you cannot truly know what shape your thyroid is in. While some of the tests are optional, the first group listed is absolutely essential for getting an accurate assessment of your thyroid function.

These tests are critical to understand your:

  • Metabolism
  • Thyroid function
  • Energy level
  • Heart rate
  • Ability to control weight
  • And more…
number 4

The Big Four

To get an accurate assessment of your thyroid issue, it is essential that you have the following four tests done:

  • TSH
  • Free T3
  • Free T4
  • Reverse T3

So what do all those letters mean? Well, we’ve already discussed TSH. That’s the hormone your pituitary gland produces to tell your thyroid to produce more thyroid hormone. “Thyroid hormone” here actually refers to two main hormones—triiodothyronine, (or T3), and thyroxine, (

or T4).

T3 is the metabolically active form of the two thyroid hormones—the stuff that kicks your metabolism into action. Yet not all of the T3 in your blood is usable by your body. Some of it is bound by protein, which makes it biologically unavailable. Only the unbound form of T3, or free T3, can be used. While doctors will often run tests to measure the total T3 in your blood—the amount bound plus the amount free—it’s free T3 that matters. So forget total T3 and find out your free T3. It’s absolutely essential to know this!

The great majority of thyroid hormone produced by your thyroid is actually T4, which is basically inactive until it is converted to T3. Like T3, T4 exists in bound and free states, and it’s the level of free T4 that counts. In fact, it’s critical to know not just the amount of free T4 and free T3 in your blood, it’s also important to know their ratio, since this reflects how well your body is converting the inactive free T4 into active free T3. Makes sense, right?

Reverse T3 is a metabolically inactive form of T3. It does not stimulate your metabolism. In fact, reverse T3 fits right into the cell receptor sites made for free T3 and blocks the free T3 from getting in! So too much reverse T3 can actually slow your metabolism. Since reverse T3 basically “cancels out” free T3, knowing the amount of reverse T3 in addition to the amount of free T3 (and free T4) is critical.

Typically we see elevated reverse T3 levels in the presence of heavy metal toxicity, hyperthyroidism (overactive thyroid), and/or extremely high or low levels of cortisol, which is produced by the adrenal glands. For more information on the thyroid-adrenal connection, see The Adrenal Fatigue-Hypothyroid Connection.

Excellent Tests To Add On


Often one of the causes of hypothyroidism is an autoimmune disorder (Hashimoto’s) whereby the body attacks the thyroid gland. Since this is so common in people with low thyroid, we at Natural Thyroid Healing initially run two labs on all of our clients in order to test for autoimmune problems.

TPO Ab (thyroid peroxidase antibody)
TG Ab (thyroglobulin antibody)

If the results of these tests come back negative, we can typically bypass them in follow-up testing, but because autoimmune problems are so common when it comes to thyroid, we know from experience that these tests are important to run at the outset in order to determine a proper treatment protocol.

Of course every person is different. So, depending on the symptoms a client is experiencing, it may be necessary to get more information through additional thyroid testing. Some good additional tests to consider, which we also check for, include the following:

  1. TAA Ab: Get this done if you’ve had trauma to your neck, throat area or thyroid gland.
  2. Thyroxine Binding Globulin: To check the levels of protein that transport thyroid hormone.
  3. Iron or Ferritin: Thyroid peroxidase activity depends on iron; therefore, iron deficiency can lead to hypothyroidism. Ferritin levels should be in the range of 90–110 mg/mL to achieve proper thyroid function.
  4. Vitamin D: Vitamin D levels need to be between 50 and 80 ng/mL for thyroid receptors to respond properly.
  5. Cortisol: Proper cortisol levels are needed for thyroid hormone to function! For more info, see the article “Thyroid-Adrenal Connection.” [link to this article]

So Why Don’t Most Doctors Run These Essential Thyroid Labs?

Often patients have a hard time getting their doctor to order all the labs needed to truly evaluate the state of their thyroid. There are several reasons for this. For one, most doctors are looking only for primary hypothyroidism, and so they order just a TSH test. Moreover, as we’ve discussed, what conventional medicine considers the high range of TSH values is completely out of whack. The truth is many people with “normal” levels of TSH are indeed suffering hypothyroidism—and going undetected!

In addition, unbeknownst to most physicians, primary hypothyroidism is just one of eight different types of low-thyroid conditions. Unfortunately, most conventional doctors are not very familiar with the nature of these conditions, and so they don’t know which labs to order to test for them.


And finally, there is the matter of insurance-company influence. Often doctors run only tests that are

considered “medically necessary” by insurance companies, allowing those companies to decide what you need for health and healing. But who is your insurance company to make this decision? It’s your body and your health, so whoever your health practitioner is, insist on getting the right tests done.

The Bottom Line Is This

If you have hypothyroid symptoms, get tested! And get the right tests. While those include the Big Four, they will probably include others, especially TPO Ab and TG Ab labs to test for autoimmune issues. At Natural Thyroid Healing, we specialize in determining precisely which thyroid labs you need, and once you’ve run those tests, we’ll help you make sense of the results and get your body back on track.

Even if you just want help ordering your tests, we can do that too…

Hypothyroidism is a serious condition. Every cell in your body needs thyroid hormone, which means every one of your organs and systems is negatively affected if your thyroid is not keeping up. Find out how simple it is to discover just what’s going on with your thyroid and your metabolism, so if there is a problem, you can nip it in the bud right now!

Leave a Comment

Your email address will not be published. Required fields are marked *