Background: I started taking T3 in June 2015 after finding that my fT3 was low in range while my fT4 was at the top; I have always felt best with TSH suppressed. As expected my fT4 fell when T3 was added, to around halfway in the normal range. All has been good since then and I have been adjusting my dose of T3 according to blood tests while leaving my dose of T4 the same.
I have regular blood tests to check serum lithium levels, but usually only TSH and fT4 are tested. I have just received a letter from my doctor as follows:
"I have received the results of your recent thyroid function test. Your TSH was suppressed at -0.03 miu/L and your T4 level was elevated at 20.5 pmol/L. I understand you feel better with a suppressed TSH. I note that we haven't tested your T3 level since November 2016 and would therefore be grateful if you could continue having six monthly monitoring of your thyroid function and this should include your TSH, T4 and T3 each time.'
Top of the fT4 range locally is 19.8; I have hovered around 15.0 since starting T3. TSH is usually around the level mentioned in the letter.
With the caveat that we don't have the complete picture without a fT3 reading, what could cause my fT4 reading (and possibly my fT3) to suddenly jump after longtime stability? I have been having hot flushes and no periods, but am also going through early menopause so put them down to that. My heart rate is about 90 BPM and I have fluttery palpitations several times a day.
It's extremely unlikely to be a sudden resurgence in my own thyroid's activity as I've had Ord's Thyroiditis for over 20 years.
Any thoughts? Thanks.
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