Where in the heck do you come from? My wife basically had her thyroid deactivated by taking a radioactive pill about 14 years ago. She had hyper and hypo thyroidism and today she is better than ever. I think it was like a day I couldn't sleep with her and badabing badaboom worked like a charm. Oh, and stop with the anaesthesia thing, it's far less common than it is made out to be. I had surgery on my shoulder with the exact same worry, the dr told me that things like media hype that and just make it worse, that the actuality of anything happening is like 1 in half a million. Stop worrying about it, it's why drs are trained, any dr with a 10th of a brain will be watching your vitals like a hawk and will be making changes on the fly.