Trapper is right on:
IMO, doctors always try and make this voodoo magic to sell drugs and fill waiting rooms. The thyroid is simply a furnace that controls body temp. Feed it Iodine & selenium, and the furnace will regulate our body temp. If it is below 98.6 then we are hypothyroid. If it is above 98.6 we are hyperthyroid.
If we feel chilly, cold hands, cold feet, it is hypothyroid. If we feel hot & sweaty, then it is hyperthyroid. Give our thyroid enough Iodine & selenium and then the thyroid should get back to normal WITHOUT drugs.
Does he drink city water with Fluoride? Or pop with bromide? Then fluoride & bromide will make his thyroid sickly: