Hi. I'm new here but have been hypothyroid for about 8 years post the birth of my second son. When I was diagnosed my TSH was probably around 18 with my main symptom being exhaustion. Anyways, I've been on thyroxine for the past 8 years (100mcg) without any issues....with my TSH hovering around 2. (sorry I don't have the T3 or FT4 results from back then). This past Xmas I've been having weird symptoms which are probably not related to thyroid but I got a full blood test anyways. In December my TSH was suddenly at 4.47 even though I've been on same medication. I got retested in January and it's now at 6.7. My GP raised my does to 112.5 mcg. Does anyone know why the TSH would be rising while I'm still on medication? Did my body just stop responding to the thyroxine? Here are the other results from my blood test:
Serum Vitamin D 60 nmol/L (50-174)
Serum folate 13.9 (doesn't give range)
Serum vitamin B12 419 ng/L (190-660)
Serum Free T4 18.2 pmol/L (10.80-25.50)
Serum ferritin 52 ug/L (13-150)
And most recently TSH is 6.67 (as of January). I've been on the higher dose for a couple of weeks and need to go back in 2.5 months for re-test.
Any insight would be greatly appreciated! Thanks.