Rising TSH

I have lived with Hypothyroidism for approximately the last 7 years and been on 75mcg of Levothyroxine since almost a year (when my dose was raised to keep my levels in check)

My TSH tested
Dec 2021 = 4.11 mIU/L
June 2021 = 3.55 mIU/L
Feb 2021 = 1.49 mIU/L

Reference Range:
0.45 mIU/L - 4.50 mIU/L


FT4 has always been within the Reference Range:11.0 pmol/L - 23.3 pmol/L
Dec 2021 =15.6 pmol/L
Feb 2021= 18.1 pmol/L

Does anyone know why T3 levels are never checked? And what needs to be done about my rising TSH? Because it looks like it will soon go over the range since it has been on the rise.

Also my GP thinks it is still normal as long as it is within the range. But last year an I was told by another GP that if I am on meds for it my levels should be no higher than 3.
So I am not sure I know who to trust here. Any thoughts around this?

Also could a CT scan cause TSH levels to rise rapidly?

Post Edited (Seeker275) : 12/12/2021 9:20:28 AM (GMT-7)

I have had myself checked twice for the 2 thyroid antibodies . When I was initially diagnosed and then about 3 years back. Both times my reports were clear.
My GP doesn’t seem keen to give me an endocrinologist’s referral because according to him it is in range so nothing to be alarmed. Last year when it was rising I managed to get an endocrinologist referral and see one but he too just said my case is very simple and didn’t think it needed further investigation. He didn’t seem keen to run any T3 tests saying they don’t consider it.
I had test my FT3 levels in 2020 through a different lab and I know they were way out of the range but because my GP doesn’t want to run this test himself making it sound like it isn’t relevant I am stuck.

My Gp has been doing the slight levy thyroxine dose increase every time it goes above 5 because when I was diagnosed I was on 25mcg of it and now it is 75mcg.With every dose change it stays stable for 6 months or so , even comes down below 2 and then gradually starts climbing again. So to me it looks like it is just buying time till the next dose change? Is your TSH suppose to stay stable for years on levy thyroxine?