Thyroid UK
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t3 levels

Just checking my most resent blood tests. My t3 levels are 4.57 range 3-500. its the first time iv had t3 checked as usually they only test t4 and tsh. As my results are closer to the top end i was wondering how other people feel with this king of reading. Iv not been feeling well for some time and wondered if this could be the cause. My tsh is 0.81 range 0.34-5.60.

3 Replies

What's your t4?


I really doubt you feeling unwell is down to the fT3 level.

Much more likely to be one or many other factors:

low iron, low cortisol, low vit D, low vit B12, low folate or other B vitamins, intolerance to the amount of T4 (levo or NDT) that you are taking are some of the most common things, however we must also remember that there are other 'conditions' apart from hypo which make people feel unwell too.


Hi I agree with above. However,make sure your FT3 does not go over, the risk of having it quite so high You need it tested in conjunction with T4 too.T4 should only be in the top thrrd of range, especially if FT3 is high.Too much T4 can push up the FT3.

Best wishes,



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