If gp says that suppressed tsh indicates hyperthyroidism (too high a dose of t3/t4) but doesn't test t3 or t4, what is the correct reply?

I'm hypo and on t3/t4 combination.

I'm under the impression that proper hypert'ism is indicated by high t3/t4, and that tsh is just a measure of a pituitary hormone. So if they try to tell me I'm overmedicated I think I'm entitled to say that you can't tell that from a tsh-only test and if you want to reduce my meds we need to see a t3/t4 test as well. Is this correct? And how might gp try to argue with me?


4 Replies

  • I think you're spot on! Just say exactly what you've said here. Where I am if the TSH is low the lab seem to automatically give T4 and T3. But if you're on a combination of T4/T3 they should be testing both anyway - TSH is even less reliable when taking T3. Have you had a TSH-only test already? Ask GP - or whoever takes the blood - to write on the form what you're taking and request both T4 and T3. If he has an argument then he doesn't know what he's talking about!

  • Well, this is my fault because I haven't yet told them I'm taking t3 (prescribed by a private doctor). I'm not sure how to go about it and I suspect that my real issue will be telling my endo because in truth my gp would rather not deal with thyroid issues and would prefer to defer to the endo (which is probably a good thing). Now I have to figure out how to deal with the endo.

    But anyway, no, I haven't yet had a tsh-only test since I've been on t3/t4 combo, but the lab refused to test my t3 and antibodies last test. I may have got a t4 result, I can't remember.

    I was just a little worried because they do seem to get interested when my results are 'abnormal' (low tsh). So far gp is mollified when I say my endo has it under control, but if the t3 affects test results I don't know if surgery will put their foot down. I have to see someone tomorrow (about something unrelated) but I want to be prepared if they start asking questions.

  • Surely without testing FT4 and FT3 there is no way to know why your pituitary has decided to reduce TSH - it could be because you have enough or even too much T3 - either produced by the thyroid or taken my mouth - or because it (your pituitary) is half dead, deaf to to the demands of the thyroid or on strike (I'm sure someone knows the technical terms for these!). TSH isn't a lot of use, really.

  • Well quite, but how to talk them into the test? Or rather how to talk the lab into the test? Maybe once they know I'm on t3 they will be able to get it done - ?

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