The Thyroid Scale™ is a method of evaluating thyroid lab data (TSH, Free T4, and Free T3) relative to optimal values as well as each other to provide a clearer view of what is going on as opposed to simply looking at whether lab values are ‘normal’ or not. Developed by Bruce Rind MD, it is used get a more thorough understanding of an integrative medical approach to identifying and correcting metabolic energy problems such as Metabolic Therapy Program:Thyroid, Adrenal & Hormone Correction.

Normal rather than Optimal
The frequently used term of ‘normal’ refers to a statistical situation. Thus, a ‘normal’ state of health probably means you have some medical problems. It may be normal to die at 76 yrs of age, but at 75 years old, you may decide that what you really want is ‘optimal’ health as opposed to ‘normal’. Normal is not the same as optimal, whether it relates to longevity of life, a body temperature or a lab test result. You may be within the "normal" range for test results and still experiencing symptoms which affect your energy and quality of life.

Thyroid levels are a critical component of determining the cause of low metabolic energy. The Thyroid Scale™ helps us compare thyroid lab values to each other and thus see their implications more clearly. It can be a line diagram or a table of lab values to visually depict how TSH, T4, and T3 relate to each other. It is an approximation. Nonetheless, as a clinical tool, it seems to be more informative than the alternative which is to call a lab value low, normal, or high.

Which test to use? I typically test for the following:

  • Routine Testing: Free T3, Free T4, TSH.
  • If there is a suspicion of Hashimoto’s Thyroiditis, I include TPO and ATA. I also use this to monitor the severity of the Hashimoto’s Thyroiditis and to see if therapy is working.
  • If there is suspicion of Grave’s Disease, I include TSI.

Which lab values are the most meaningful? Lab reports tend to provide only the high and low limits of ‘normal’ values. Since we are striving for ‘optimal’, the ranges for optimal are noted below along with standard lab high and low values. These optimal range values are based on my observation of nearly 5,000 patients and reflect the lab test values that my healthiest patients tended to have. Remember that the optimal zone is an approximation and that it is meant to be used as a rough guide. Note that laboratory techniques for these tests vary and lab values may have a 5-10% margin of error depending on the laboratory used.

Test Lab Low Optimal Range Lab High
TSH 0.5 1.3-1.8 5.0
Free T4 0.8 1.2-1.3 1.8
Free T3 230 320-330 420
Free T3* 2.3 3.2-3.3 4.2
*Some labs divide FT3 results by 100 thus 230 is the same as 2.3, etc.

In the cases of Free T4 (FT4) and Free T3 (FT3), the optimal zone is roughly half way between the usual lab normal Low-High values. Note that the normal range for these hormones may change a bit from lab to lab. In the case of TSH, the optimal zone is skewed far toward the low end of the standard lab Low-High range.

Defining the Thyroid Scale

The Thyroid Scale™ is a powerful tool. It is a relative (to optimal) scale that converts different thyroid hormone values to a common unit of measurement. By looking at values relative to optimal (and each other) on a common scale, one can obtain a clearer picture of what is going on.

On the relative scale, zero (0) reflects the optimal range. The higher the number (positive or negative) on the relative scale the further the value is from optimal. Plus and minus five (+/- 5) reflect the ‘normal range’ of typical lab High-Low values, respectively.

Using a fairly proportional distribution between Low and High lab values relative to Optimal, the relative scale lab value ranges are as follows.

Thyroid Scale™  Range Values
Simply plot the different hormone lab values on the relative scale using the provided lab value ranges. Remember that this is not an exact science and that the purpose of the relative scale is to help us understand where lab values sit relative to optimal and then each other. There needs to be sufficient detail to do this but not so much detail that the scale becomes too cumbersome. The below diagram shows an example of a completed Thyroid Scale™ diagram for what may be a metabolically healthy individual – the T3, T4, and TSH are all in the optimal zone.

Thyroid Scale™ Extracting New Meaning from Labs
The Thyroid Scale™ is a powerful tool that provides us an idea of what our lab data actually means by simply plugging in some thyroid lab values (TSH, TT4, and TT3). As stated earlier, this data can be critical in determining the cause of low metabolic energy. Therefore, as your adrenals and thyroid receive the needed support revisit this tool as your lab values change.