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 because they know they are different. Describing their TSH and thyroid hormones is its own … Continue reading Pediatric and teenage TSH, FT4, and FT3 levels
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 TSH is one of many factors that can make this screening test less accurate (Ling … Continue reading Age bias may hide hypothyroidism under a normal TSH
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 of TSH (and Free T4) as "in or out of range" to classify people as … Continue reading Can a normal TSH rule out thyroid disease?
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. A TFT panel typically includes thyroid-stimulating hormone (TSH, thyrotropin) and thyroxine (T4), and triiodothyronine (T3) depending on local laboratory policy." (Thyroid Function … Continue reading What’s wrong with calling TSH, FT3 and FT4 “thyroid function tests”?
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 a problem for the heart, the liver, the kidney, the brain, and so on. It … Continue reading Are normal thyroid reference ranges risk-free zones?