Normal thyroid physiology and pathophysiOlogy with reference to non-thyroidal illness is reviwed, including infections, specific disease states and drugs and their effects on thyroid function tests. A review of the literature reveals that following almost any infection the serum T4 and T3 decrease as a result of diminished secretion of TSH and thyroxine, accelerated T4 disappearance, inhibition of hormone binding to transport proteins and decreased peripheral T4 to T3 conversion. [Abbreviated Abstract. Open document to view full version]
