I have had Graves’ Disease for 15 years, and had RAI (and subsequent treatment with thyroid hormone). My thyroid functions change from time to time for no apparent reason. I’ve had to have my dosage increased, then decreased, then increased again, etc. I will go for several years where everything is fine and then suddenly something changes. By this time you’d think I’d be so used to the symptons of change that I’d recognize them immediately, but it happens gradually and is usually detected by routine blood tests. Afterward I’ll realize THAT’s why I was so tired or why my legs were so weak (if hypo) or why I was sweating so much (if hyper). There were times I have looked at a flight of stairs and thought I couldn’t possibly climb them. I guess this is just an ongoing process.