Author Archives
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Age, sex and TSH-FT4-FT3 relationships: Advanced lessons
No one wants to be ageist or sexist in thyroid screening or diagnosis. But if we are blind to the way that age and sex can distort the hypothalamus-pituitary-thyroid (HPT) axis, our interpretations of thyroid hormone levels and TSH will… Read More ›
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Pediatric and teenage TSH, FT4, and FT3 levels
Scientists that study the effect of age on thyroid-stimulating hormone (TSH), Free T4 (FT4) and Free T3 (FT3) thyroid hormones often exclude the age group from birth up to age 16, 18, or 19. They usually exclude children and teenagers… Read More ›
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Age bias may hide hypothyroidism under a normal TSH
Scientists have been explaining that TSH responds to thyroid hormones differently in childhood, early adulthood, late adulthood and very advanced age. This poses a problem for regions that have implemented TSH-only screening for thyroid dysfunction. The effect of age on… Read More ›
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Can a normal TSH rule out thyroid disease?
If you are well-informed by current thyroid science, you already know the answer to the question in the title. “No. A normal TSH cannot rule out thyroid disease.” Since the 1990s, physicians have been taught to use simplistic category-based interpretations… Read More ›
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What’s wrong with calling TSH, FT3 and FT4 “thyroid function tests”?
A Google search for “thyroid function tests” brought up a definition square at the top of the search results. It says that “Thyroid function tests” is a collective term for blood tests used to check the function of the thyroid…. Read More ›
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Are normal thyroid reference ranges risk-free zones?
Commonly, when scanning laboratory results, a physician will look for values that are “out of range” (high or low). It is often presumed that if FT4, TSH, and FT3 are all “in the normal range,” those hormone levels won’t be… Read More ›
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Reference list for analyzing normal thyroid lab results
This list provides all references in alphabetical order for the following series of posts: Series introduction: Cognitive barriers to analyzing “normal” thyroid lab results Barrier 1: Are normal thyroid reference ranges risk-free zones? Barrier 2: What’s wrong with calling TSH,… Read More ›
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Cognitive barriers to analyzing “normal” thyroid lab results
Here is a common moment that occurs now and then in doctor’s offices. The physician looks up from their computer screen and tells the patient, “Your thyroid function tests came back normal, so nothing is wrong with your thyroid.” That… Read More ›