can hyperthyroid return years later after radioactive treatment

[Brenda1935]

Was diagnoised at 18 with hyperthyroid, treated by radioactive iodin, never had any issues with thyroid since then. Now 53 years old and tsh levels are dropping. Aug 2017 tsh1.58, t3 andt4 good. Feb 2018 tsh 0.68 t3/t4 not tested, April 2018 tsh 0.22, Ft3 within normal range Ft4 above normal range19.29. Excessive hot flashes, can sleep, moody, losing inches, feel noise in left ear. Did start using Vagifem in Aug. was wondering if anyone else has had this happen.

[bantam12]

So presumably the RAI didn't totally kill off your thyroid if you haven't needed replacement meds since, in which case I imagine entirely possible to go hyper again. I relapsed some 30 years after a partial thyroidectomy and then had RAI which sent me hypo immediately.