Standard thyroid tests such as TSH and T4 may miss low thyroid conditions, while T3 and reverse T3 testing often tells a more accurate story.
There are numerous, well documented reasons for this disparity. Conditions that are shown to cause disruption of standard thyroid testing include:
- physiologic and emotional stress
- depression
- dieting
- obesity
- leptin or insulin resistance
- diabetes
- chronic fatigue syndrome and fibromyalgia
- inflammation and autoimmune disease
- system illness
- low testosterone or growth hormone
- aging
Thyroid testing should always include “free T3” and “reverse T3” levels, in addition to the standard TSH and T4 levels. Thyroid replacement therapy often needs to rely on prescription T3 (liothyronine) in order to truly achieve normal thyroid status.
For more information see our article on Thyroid Hormone Chemistry and Thyroid Tests.
For VERY detailed information and references to published literature regarding this topic please refer to published studies by thyroid expert and colleague, Dr Kent Holtorf:
Peripheral-Thyroid-Hormone-Conversion-and-Its-Impact-on-TSH-and-Metabolic-Activity
Thyroid-Hormone-Transport-into-Cellular-Tissue
