Re: How quickly does TSH change?
TSH isn't static. Untreated, it can change as much as 3 full points in only a 24-hour period. It's higher in the a.m. and gradually tapers off through the day until it begins to rise again around 9 p.m.
When I was first diagnosed hypo, my TSH was just under 7.0. I took a small dose of Synthroid for about 3 months and my TSH became suppressed to just .02. After stopping the Synthroid, my TSH was back to 7 within one month. That's how fast it can change.
You're not just "leaning" toward hypoT with a TSH of 2.5. You probably are hypothyroid. If you're having symptoms, and aren't being treated with supplemental hormone, poke that MD with a stick until he writes you a prescription!