Your thyroid is a crucial gland that manufactures vital hormones involved in various physiological systems in your body. It is when this gland starts to produce too much or too little of certain hormones that thyroid illnesses begin to occur.
With this in mind, how do you know when you’re suffering from one thyroid disease or the other?
This is where thyroid blood tests come in. Thyroid blood tests are a range of blood tests used to measure the level of thyroid hormones in your blood.
They help determine if your thyroid gland is functioning normally. These tests include TSH, free T3, free T4, total T3, total T4, and RT3 tests. Tests for thyroid-stimulating immunoglobulins (TSI), thyroid antibodies, and thyroid binding proteins are also necessary.
Why should you take all these tests? First off, research has it that 20 million people in America suffer from thyroid malfunction. The interesting part is that 60% of this figure are clueless about having thyroid disease.
Do you know why taking this test is important? The tests will give you valuable information about whether or not you have a thyroid malfunction. That way, you can begin treatment as quickly as possible.
However, to get the best of your thyroid test results, you need to not only take the blood test correctly but also interpret them appropriately.
That’s is why this article is so important. Here, we discuss each one of the necessary thyroid function tests and share a comprehensible guide on how you can understand your thyroid test results. Ready? Let’s move!
That’s is why this article is so important. Here, we discuss each one of the necessary thyroid function tests and share a comprehensible guide on how you can understand your thyroid test results. Ready? Let’s move!
Blood Tests for Thyroid Function
If you’re going to evaluate your thyroid, it’s important that you take the full thyroid panel! You see, many physicians will not order a complete thyroid lab panel and instead will focus only on 1-2 standard tests.
What most patients don’t know is that ordering the full panel is more beneficial, especially if you’re testing for the first time. This is the only way you can come close to uncovering common thyroid disease patterns observed in a variety of illnesses.
However, without a good understanding of why each of these tests is so important, you cannot confidently request the complete tests. Therefore, this section explains what each of these blood tests means and why it’s essential to test for them when evaluating your thyroid function.
What most patients don’t know is that ordering the full panel is more beneficial, especially if you’re testing for the first time. This is the only way you can come close to uncovering common thyroid disease patterns observed in a variety of illnesses.
However, without a good understanding of why each of these tests is so important, you cannot confidently request the complete tests. Therefore, this section explains what each of these blood tests means and why it’s essential to test for them when evaluating your thyroid function.
TSH (Thyroid Stimulating Hormone) Test
Also known as thyrotropin, TSH (thyroid-stimulating hormone) is produced in a gland located in the brain, and this gland is called the pituitary.
The pituitary gland secretes TSH into the bloodstream, where it travels to the thyroid gland and informs it to secrete the amount of thyroid hormone that your body needs.
TSH’s primary function is to increase thyroid gland production of T4 (thyroxine) and T3 (triiodothyronine) thyroid hormones. As such, when your TSH is increased beyond normal, that’s a sign that your thyroid is underactive. On the other hand, when it is decreased, your thyroid may be overactive.
When evaluating thyroid function, doctors focus a lot of attention on TSH. Despite its usefulness in evaluating patients, the TSH may not be the best or most appropriate tool for detecting and treating thyroid disorders. Why is this?
The biggest flaw is that the TSH test alone doesn’t give you the whole picture about the health of your thyroid.  Research says TSH can give you an indication of how well your thyroid gland is working.
However, the problem is that it says nothing about other factors like thyroid status in peripheral tissues, thyroid hormone conversion, and thyroid hormone cellular activation.
Beyond all these, there’s also the matter of suppressed TSH, also known as subclinical hyperthyroidism and hypothyroidism, which refers to a condition in which the body’s TSH level is lower or higher than it should typically be while T4 and T3 levels are normal.Â
TSH suppression can be induced by taking too much thyroid medication or other drugs like glucocorticoids, dopamine agonists, somatostatin analogs, and rexinoids. It can also be caused by a grave’s disease.
The pituitary gland secretes TSH into the bloodstream, where it travels to the thyroid gland and informs it to secrete the amount of thyroid hormone that your body needs.
TSH’s primary function is to increase thyroid gland production of T4 (thyroxine) and T3 (triiodothyronine) thyroid hormones. As such, when your TSH is increased beyond normal, that’s a sign that your thyroid is underactive. On the other hand, when it is decreased, your thyroid may be overactive.
When evaluating thyroid function, doctors focus a lot of attention on TSH. Despite its usefulness in evaluating patients, the TSH may not be the best or most appropriate tool for detecting and treating thyroid disorders. Why is this?
The biggest flaw is that the TSH test alone doesn’t give you the whole picture about the health of your thyroid.  Research says TSH can give you an indication of how well your thyroid gland is working.
However, the problem is that it says nothing about other factors like thyroid status in peripheral tissues, thyroid hormone conversion, and thyroid hormone cellular activation.
Beyond all these, there’s also the matter of suppressed TSH, also known as subclinical hyperthyroidism and hypothyroidism, which refers to a condition in which the body’s TSH level is lower or higher than it should typically be while T4 and T3 levels are normal.Â
TSH suppression can be induced by taking too much thyroid medication or other drugs like glucocorticoids, dopamine agonists, somatostatin analogs, and rexinoids. It can also be caused by a grave’s disease.
T4 (Thyroxine) Test
A T4 test measures the amount of the T4 hormone in your blood. Doctors typically test for T4 alongside TSH. Thyroxine is one of the two main hormones that the thyroid gland produces.
And it is known to increase numerous enzymes that produce energy for the body. The T4 test is therefore instrumental in evaluating thyroid function and diagnosing thyroid disease.
And it is known to increase numerous enzymes that produce energy for the body. The T4 test is therefore instrumental in evaluating thyroid function and diagnosing thyroid disease.
Here’s one thing to keep in mind: T4 isn’t as biologically active as T3. This means it has different biological effects than T3 and does not activate your cells in the same way. This begs the question, what purpose does T4 have?
It’s simple. T4 levels are still crucial for normal thyroid function because the body needs to have T4 to make T3. Also, T4 has some cellular activity; it just isn’t as potent as T3.
There are two types of T4 hormone tests:
There are two types of T4 hormone tests:
- Free T4 (FT4) test: Free T4 is the variant of T4 that is free. it means this T4 variant can enter your body tissues where it is needed and alter these tissues. This test is frequently chosen over a total T4 test since free T4 is what your body can use.
- Total T4 test:Â On the other hand, a total T4 test measures both the free T4 and the bound T4. Bound T4 is T4 that is bound to proteins and hence is unable to enter bodily tissues. Interestingly, 99% of your T4 is in this bound form. While a free T4 test can give some insight into your thyroid health, a total T4 test that measures both your free and bound T4 is quite useful.
T3 (Triiodothyronine) Test
T3 is the most potent thyroid hormone produced by your body. Under the effect of TSH, your thyroid gland creates T3 thyroid hormone directly. You probably are wondering what the big deal about this hormone is. Well, through nuclear receptors, this hormone affects practically every cell in your body.
When you consider that it is more active than T4 and is the hormone that our body can use, then it makes sense that doctors should test for T3 hormone during thyroid lab tests.
Research has it that a variety of conditions can cause thyroid dysfunction, and this dysfunction may not be detected with routine TSH testing until free T3 is measured.
Like T4, T3 tests also come in two forms: free T3 and total T3 tests. Here’s a breakdown.
Free T3
This is the quantity of active thyroid hormone that isn’t bound. The amount of free T3 in your blood provides you a sense of how active your thyroid is at the cellular level.
But you can only measure the amount of free and active thyroid hormone available to your body by measuring free T3. It’s the hormone in charge of adhering to the surface and nucleus of your cells and causing genetic alterations in those cells.
But you can only measure the amount of free and active thyroid hormone available to your body by measuring free T3. It’s the hormone in charge of adhering to the surface and nucleus of your cells and causing genetic alterations in those cells.
It is, therefore, reasonable to claim that a free T3 test is one of the most useful (if not the most useful) tools for determining T3 availability in your system and the state of your thyroid health, especially in the short term.
Total T3
This test determines the total quantity of T3 in the bloodstream. In other words, it measures the FT3 and the bound T3. Bound T3 is T3 fused to protein and therefore not available to be used by the body.
RT3 (Reverse Triiodothyronine) Test
The Reverse T3 (RT3) test is done to measure the inactive form of the hormone T3 or Triiodothyronine in the body. Reverse T3 is an anti-thyroid metabolite that is produced when T4 undergoes conversation. If this is a little confusing, don’t worry. You’re probably wondering, isn’t T3 what is produced when T4 converts?
Well, yes, but we’ll explain. You see, your body has the power to convert T4 to either reverse T3 or T3. If it picks reverse T3 over T3, it means that that molecule of thyroid hormone can’t be activated and made into T3. But that’s not even everything.
Well, yes, but we’ll explain. You see, your body has the power to convert T4 to either reverse T3 or T3. If it picks reverse T3 over T3, it means that that molecule of thyroid hormone can’t be activated and made into T3. But that’s not even everything.
The prevailing agreement among experts is that RT3 assays are of limited clinical use because to them, it has little biological activity and is an inactive compound. But this is not exactly accurate.
This study shows that T3 and reverse T3 often compete for cellular binding. Plus, by converting T4 to reverse T3, your body lowers your circulating T3 levels while also making it more difficult for the remaining T3 to connect to and activate your cells.
This is why holistic health practitioners consider reverse T3 an anti-thyroid metabolite. By “anti-thyroid metabolite,” we mean that RT3 is the hormone your body appoints to slow down thyroid activity. But why would your body need to slow down thyroid function anyway?
It’s because when you’re severely I’ll, your body can’t afford to overwork itself and burn energy as it’ll normally do when you’re healthy. For this reason, your body makes RT3 slow down your metabolism so your immune system can get more energy and help you heal faster.
The problem, however, is that your body doesn’t make RT3 only when you’re ill. Other things like dieting, inflammation, nutrient deficiency, stress, intestinal dysfunction, and sleeplessness can trigger it.
And when it does, you’ll begin to have symptoms like low metabolism, weight gain, tiredness, pain, anxiety, depression, etc. Notice how those look like symptoms of hypothyroidism?
This study shows that T3 and reverse T3 often compete for cellular binding. Plus, by converting T4 to reverse T3, your body lowers your circulating T3 levels while also making it more difficult for the remaining T3 to connect to and activate your cells.
This is why holistic health practitioners consider reverse T3 an anti-thyroid metabolite. By “anti-thyroid metabolite,” we mean that RT3 is the hormone your body appoints to slow down thyroid activity. But why would your body need to slow down thyroid function anyway?
It’s because when you’re severely I’ll, your body can’t afford to overwork itself and burn energy as it’ll normally do when you’re healthy. For this reason, your body makes RT3 slow down your metabolism so your immune system can get more energy and help you heal faster.
The problem, however, is that your body doesn’t make RT3 only when you’re ill. Other things like dieting, inflammation, nutrient deficiency, stress, intestinal dysfunction, and sleeplessness can trigger it.
And when it does, you’ll begin to have symptoms like low metabolism, weight gain, tiredness, pain, anxiety, depression, etc. Notice how those look like symptoms of hypothyroidism?
Well, that’s why your level of RT3 should never be taken lightly. Even if your T3 levels are within normal limits, if you have too much reverse T3 in your body, it can cause hypothyroidism symptoms.
In such circumstances, naturopathic doctors say it’s critical to examine both reverse T3 and T3 itself so that the two can be viewed in context.
It’s critical to figure out why reverse T3 levels are higher than free T3 levels because identifying the reasons for the problem is critical to solving it. Licensed naturopathic doctors (NDs) place so much emphasis on treating the disease’s underlying causes.
As such, whether it’s stress, inflammation, insulin resistance, or nutritional difficulties, addressing these root causes can help control thyroid hormone metabolism and, in the best-case scenario, promote T4 conversion to T3, the more active form.
T1 and T2
Thyroid hormone production produces T1 and T2, which are hormone precursors and by-products. They don’t seem to affect the thyroid hormone receptor and appear to be completely inactive, which is why these two thyroid hormones aren’t usually tested.
They have, however, been discovered to stimulate the processes of the enzyme that changes T4 to T3, implying that they aid in this crucial conversion process. Asides from this, T2 also improves liver metabolism as well as the metabolism of the heart.
They have, however, been discovered to stimulate the processes of the enzyme that changes T4 to T3, implying that they aid in this crucial conversion process. Asides from this, T2 also improves liver metabolism as well as the metabolism of the heart.
TSI (Thyroid Stimulating Immunoglobulins) Test
Thyroid-stimulating antibodies (TSIs) are antibodies that erroneously instigate the thyroid gland to become more active and release more thyroid hormone than your body needs into the bloodstream.
As such, a TSI test is done to measure the level of thyroid-stimulating immunoglobulin in your blood.
If you have hyperthyroidism symptoms and your doctor suspects you have Graves’ disease, they will usually conduct a TSI test. If your TSH, T3, or T4 levels are abnormal, then conducting this test can help your doctor figure out what’s causing your symptoms.
As such, a TSI test is done to measure the level of thyroid-stimulating immunoglobulin in your blood.
If you have hyperthyroidism symptoms and your doctor suspects you have Graves’ disease, they will usually conduct a TSI test. If your TSH, T3, or T4 levels are abnormal, then conducting this test can help your doctor figure out what’s causing your symptoms.
Thyroid Antibodies (TgAb) Test
The thyroid antibodies test is done to determine the level of thyroid antibodies in your blood. Antibodies are proteins produced by the immune system which under normal circumstances, combat external invaders such as viruses and bacteria.
However, the problem is these antibodies can accidentally assault the body’s own cells, tissues, and organs. Thyroid antibodies attacking healthy thyroid cells can cause an autoimmune thyroid disease which, if left untreated, can lead to significant health issues. Research shows that TgAb levels are elevated in 20-40% of patients with Graves’ disease.
Thyroid antibodies come in a variety of forms: antibodies that destroy thyroid tissues, antibodies that induce excessive production amounts of thyroid hormones, and others. Here are brief explanations.
However, the problem is these antibodies can accidentally assault the body’s own cells, tissues, and organs. Thyroid antibodies attacking healthy thyroid cells can cause an autoimmune thyroid disease which, if left untreated, can lead to significant health issues. Research shows that TgAb levels are elevated in 20-40% of patients with Graves’ disease.
Thyroid antibodies come in a variety of forms: antibodies that destroy thyroid tissues, antibodies that induce excessive production amounts of thyroid hormones, and others. Here are brief explanations.
Thyroid Peroxidase Antibodies (TPO)
Thyroid peroxidase (TPO) is a naturally secreted enzyme in the thyroid gland and is a crucial component of thyroid hormone synthesis. A TPO test aims to detect the amount of antiboty working against this vital enzyme.
Thyroglobulin Antibodies (Tg)
This antibody works against thyroglobulin, which is thyroid hormone in storage form. This test helps diagnose and treat people with thyroid cancer.
Thyroid-stimulating Hormone (TSH) Receptor
This includes two forms of autoantibodies that bind to thyroid proteins that TSH typically interacts with.
Thyroid Binding Inhibitory Immunoglobulin (TBII)
This prevents TSH from attaching to receptors, causing hypothyroidism by preventing thyroid hormone production.
Thyroid Binding Proteins Test (TBG)
Thyroid-binding globulin (TBG), also known as thyroid-binding protein, is a liver-produced protein. Its job is to bind T4 and T3 and transport them through your blood.
This way, they can moderate your metabolism and conduct other essential activities. When a serum TBG level test, also known as the thyroxine-binding globulin test, is performed, the aim is to ascertain the amount of TBG protein in your blood.
This way, they can moderate your metabolism and conduct other essential activities. When a serum TBG level test, also known as the thyroxine-binding globulin test, is performed, the aim is to ascertain the amount of TBG protein in your blood.
The test also helps point out other illnesses that may affect the amount or activity of thyroid hormones in your blood. TBG values may not carry so much weight in hypothyroidism or hyperthyroidism caused by thyroid gland malfunction.
They’re particularly significant if you have aberrant T3 or T4 levels but no symptoms of thyroid dysfunction. Look at it this way. When TBG levels are high, the TBG binds to more thyroid hormone, resulting in less free thyroid hormone circulating in the blood.
This causes the body to produce more thyroid-stimulating hormone, which causes more thyroid hormone to be produced. Even if the person does not have hyperthyroidism, the total thyroid hormone level will be increased.Â
To be continued…
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