Thyroid function after RAI

[ReneeC76]

I've read comments here from people who don't believe their thyroid was "dead" for some years after RAI. So far, online and in the books I'm reading, I'm not able to find a whole lot of info on this. Does anyone know how a person would find out if the symptoms they suddenly began having post RAI were from either their thyroid still having some function, or even possibly from the last tissue in their thyroid finally dying off? Does anyone have experience with this or know of any info to share?

[Lalatoot]

I was led to believe when I had RAI that the dose you were given was tailored to the individual and that it was to reduce the thyroid not to kill it off entirely. The endo also said that for a few this meant they ended up with adequate thyroid function but for most they ended up hypo to some degree. Certainly my expectation was some residual thyroid function.

Post RAI it took 3 months for my levels to plummet which they did quite suddenly. 4 years later I am on a combo of t4 and t3 and trying to find a balance in levels.