Stacestar, I would also encourage you to take a good look at his throat area - does it look swollen around his thyroid area? If you believe that it might be, please don't hesitate to have that checked out as well. Just be sure that they check both T3 & T4, not just TSH.
You can read more about
this here:
www.stopthethyroidmadness.com/tsh-why-its-useless/ Here is a link to a page where others tell of their childhood adrenal/thyroid issues if you are interested:
www.stopthethyroidmadness.com/signs-no-one-caught/ The one good thing your son has going for him is that he is young & he hasn't lived with this for decades. You have saved him a lot of misery - take my word for it!! He will heal much better and more completely because of this - so pat yourself on the back for being aware enough to see it and not just telling yourself that "he'll grow out of it" or whatever.