Diagnostic concepts like "subclinical hypothyroidism" have become cognitive barriers to understanding the adaptations and dysfunctions of the aging hypothalamus-pituitary-thyroid (HPT) axis. Thyroid diagnostic categories are usually based on whether TSH and FT4 are in range, above range, or below range, in relation to an age-blind reference range. These are convenient biochemical stereotypes. These stereotypes have … Continue reading Four types of unstable thyroid function in the elderly
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
Too many diagrams focus on the "HPT axis," in which the Hypothalamus, the Pituitary, and Thyroid gland are the biggest icons. Take for example this diagram from Ortiga-Carvalho's chapter in a physiology textbook. The huge, super-ballsy pituitary. Seriously? In diagrams like these (this is not the only such pictorial), the truly pea-sized TSH-secreting pituitary gets … Continue reading Visual bias: The pituitary gland in HPT axis diagrams
You've just come to your doctor for your annual check-up. Either you feel fine and you want to get a renewal of your current thyroid prescription, or you feel rather hypothyroid and you're hoping to get an increased dose. But your doctor has been trained to say this: "Your TSH is below reference (or too … Continue reading 7 ways to raise TSH without reducing thyroid dose
Does the statistically-defined "normal" TSH reference range for the healthy population describe the TSH range for a healthy individual? Does having a TSH within the normal laboratory range always mean you, as an individual are biologically euthyroid? Does falling outside statistical TSH normality really mean that you are hypothyroid or thyrotoxic? This is part 2 … Continue reading Relational Stability, Part 2: Normality of TSH and thyroid hormones
