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Thyroid UK
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T4 and THAB blood test


Still on my journey to getting to the bottom of my symptoms...

I saw the Rheumatologist before Christmas who has ordered more tests due to raised Smooth muscle antibodies along with raised ANA weakly speckled. She thinks I may now have Sjrogrens. I noticed my referral was 'general tiredness' but I explained to the consultant that my main reason for going to the docs over the last few years was due to the numerous Hypothyroid symptoms I have, the tiredness has just worsened this last year. So she agreed to test T4 and THAB, so to cut a long story short, is it advisable to take these early morning and fasting just like I was advised to for the TSH test?

Many thanks for any advice.


2 Replies


The lab may test TSH anyway. If you are trying to get a diagnosis it would be safer to test early and fast. FT4 and antibody levels don't fluctuate throughout the day as TSH and FT3 do so if you are quite certain TSH isn't being tested you can have the blood test any time of day.


Hi clutter. Thank you. I cannot see TSH on the form but i think i will do anyway to be sure.




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