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Advanced Thyroid Testing

woman filling out formWhy are we talking about advanced thyroid testing? If you’ve had your thyroid function tested and your doctor has told you everything is fine, yet you still don’t feel well, I’m here to tell you there is a reason – and it’s not that it’s all in your head! Unfortunately, for many patients when your standard thyroid lab tests come back normal, your doctor tells you there’s nothing wrong with your thyroid. But, that’s not necessarily the case. You see, there are two big problems with the standard lab tests most doctors order to assess thyroid function.

The first is that typical standard tests do not measure the most important markers we need to gain a complete picture of how the thyroid is functioning. The second is that the lab range for “normal” results is far too large. To truly understand if the thyroid is functioning properly, advanced thyroid testing in the lab is often necessary. In our clinic, we offer these advanced tests and develop a treatment plan based on the results.

Let me explain a bit more about the difference in how we test thyroid function compared to the usual tests most doctors order for their patients.

The Problem With Standard Thyroid Lab Tests

Mainstream medical lab testing normally assesses thyroid function by testing levels of only three markers: T4, Free T4 and Thyroid Stimulating Hormone (TSH). Let’s take a look at what these three markers actually measure.


Most primary care physicians look at T4 levels because hypothyroidism is typically treated with this form of the hormone. In fact, 95 percent of prescription thyroid medications (including Levothyroxine, Levoxyl, Synthroid, etc.) are made of synthetic T4! The problem is T4 is not very active and needs to be converted to the more active form of T3 to have a meaningful effect on the way your body feels. If your body is not converting T4 to T3, then you may STILL FEEL POORLY DESPITE NORMAL LAB RESULTS!

Free T4

This measures how much access your body has to the active form of T4. If your T4 levels are “normal,” then your Free T4 may also be in the “normal” range. So, your test results may come back “normal,” yet you could be in the early stages of thyroid dysfunction! Also, this test will not show if there is a lack of T3 (the active form of T4) in your body.

Thyroid Stimulating Hormone (TSH)

This hormone is actually released from your brain and communicates with your thyroid. I like to describe TSH as your brain’s voice: the higher your level of TSH, the louder your brain is yelling at your thyroid gland to work. The biggest problem with standard TSH testing is that the result range considered “normal” is simply TOO LARGE! Most labs give a normal range as .45-4.5 mIU/L. However, research has linked TSH levels of 2.5-3.5 mIU/mL with a significantly increased risk of dying from a heart attack or stroke. And, patients who test above 1.5 mIU/L often suffer from symptoms of low thyroid function, despite results in the “normal” range. In our clinic, we prefer to use a much narrower optimal TSH range of 0.5-1.5 mIU/L. My experience is there is a big difference in the way a patient feels when they go from a TSH level of 4.2 to 1.2 mIU/L!

Why Advanced Thyroid Testing In The Lab Can Be Your Key To Wellness

Our clinic offers advanced thyroid testing to gain the entire picture of how your thyroid is functioning, so we can develop the right treatment plan to get you on the path to wellness. Tests we offer include:

Free T3

As I mentioned earlier, this is the most active form of thyroid hormone — and often the missing link between testing “normal” and feeling normal. It’s plain and simple: Your body needs to convert T4 into T3 for you to feel well. This conversion takes place typically in the liver, kidney or gut. Have you ever thought that maybe your thyroid problem might not be a thyroid problem, but a conversion problem because your liver, kidney or gut are not functioning properly? Many people don’t think about this, but if it’s a conversion problem, then treating the thyroid with hormone replacement isn’t going to help.

Total T3

This lab shows us the total amount of metabolically active thyroid hormone there is in the body. It allows a doctor to check your body’s ability to convert T4 to T3 and rule out an overactive thyroid.

T3 Uptake

This tells us how much access your body has to T3. Low levels of T3 Uptake can mean underlying issues — such as excess estrogen, inflammation, high cortisol (stress hormone) and liver dysfunction — are denying your body access to T3. This test gives us a picture of what’s going on “beyond the thyroid,” which standard lab tests fail to do.

Reverse T3

Your body gets rid of unneeded T4 by converting it to Reverse T3. High levels of Reverse T3 can indicate problems such as high cortisol levels and/or chronic stress that need to be addressed.

Thyroid antibodies

If levels of these antibodies are high, it typically indicates the problem IS NOT with the thyroid itself, but instead is due to an autoimmune condition, meaning the body is attacking the thyroid. Hashimoto’s disease is by far the most common autoimmune condition associated with low thyroid function. Once we discover a patient has Hashimoto’s, we don’t treat the thyroid, but instead treat the immune system – which is where the problem is occurring.

Beyond The Thyroid

Often, our patients with thyroid problems think their fatigue is because of their thyroids. However, we are finding in many cases it’s not just the thyroid causing problems, but other factors such as nutritional deficiencies, candida overgrowth, food sensitivities, inflammation, oxidative stress, and non-thyroid hormonal problems including issues with adrenal or sex hormones.

Here is a small list of additional tests we can run to determine what is causing your health challenges:

  • Food sensitivity testing
  • Candida/yeast testing
  • Complete urine hormone profile (this is extremely important to discover if you have cancer-related estrogens or protective estrogens)
  • Adrenal hormone testing
  • Complete nutritional testing
  • Heavy metals testing
  • Toxic chemical exposure testing and more …

As you can see, there are many other conditions that can cause or mimic low-thyroid symptoms. This is why it’s so important to sit down and talk with a board-certified functional medicine practitioner who is trained to assess your history and current symptoms to see what testing options are best for you.

If you have questions or want to schedule a free consultation, contact us at (636) 978-0970 or click HERE to schedule an appointment.


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