Can you be hypothyroid if your TSH is normal? What factors other than thyroid hormones can affect TSH levels?
That’s what Raymond Peat (PhD) says about it:
Aging, infection, trauma, prolonged cortisol excess, somatostatin, dopamine or L-dopa, adrenaline (sometimes; Mannisto, et al., 1979), amphetamine, caffeine and fever can lower TSH, apart from the effect of feedback by the thyroid hormones, creating a situation in which TSH can appear normal or low, at the same time that there is a real hypothyroidism.
I would also add to that list iodine supplements, such as Lugol’s solution, KI (Potassium Iodide) or seaweeds (if consumed in high quantity).
