I wonder if anyone may be able to shed some light on this for me. I have had an underactive thryoid for about 13 years. My thyroxin dose has very slowly increased from 50mcg to 125mcg in that time. A couple of months ago I had my annual blood test and my TSH level had suddenly increased to 52. My GP thought it must be a mistake so re-tested and it came back as 47. She therefore increased my dose from 125mcg to 150mcg which I've been on for 4 weeks. I've had my re-test done and just got the results back and I've now gone the other way and am overactive. My results/ranges are as follows:
TSH range 0.35-4.94. Previous test 47. New test 0.19
T4 range 9-19. Previous test 11. new test 29
Does anyone understand why my TSH could suddenly go so high in the first place and then with just a small increase of medication suddenly go so low? My GP doesn't understand why and has just told me to go back to 125mcg.