I've been on 150 mcg thyroxine for around 30 years. My reading over the years have been within range then went down to 0.01 but as I felt absolutely fine my long term doctor said it was okay to stay on that dose. Now another doc has said I should reduce the dose to 125mcg which I eventually agreed to. After 3 months my blook test had TSH of 0.03 and doc called me saying I should reduce to 100mcg to get within range. I was actually going to say I wanted to go back to 150 mcg as I had started to feel a little colder and slow.
What I want to know is why my readings would start to decrease. I had RAI nearly 40 years ago but is there any possibility of any residual thyroid making a comeback?