OP, I have a 23-year-old son who has similar mysterious thyroid-related health problems that came on gradually over about a decade and then suddenly about a year and half ago. He hasn't been admitted to the hospital, but we've been in and out of the ER and seen lots of different doctors. He's taking levothyroxine now and a beta blocker so that his symptoms are under control, but he still struggles.

There are conditions of the thyroid (thyroid storm, for one) that can cause a medical emergency.

Have they determined whether your son's thyroid is under- or over-active?

I hope they figure it all out and that your son is better soon!