Thyroid UK
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T3 blood results

I have recently had blood results as follows:-

Free T3 - 3.6 (3.1 - 6.8)

TSH 0.04 (0.27 - 4.20)

Free T4 - <2 (11.0 - 25.0)

I currently only take T3 but I have been suffering with urticaria and angioedema, my dermatologist thinks it could be to do with my thyroid and wants me to go back on t4.

Any help in understanding theses results would be most appreciated.

Thanks Jay-jay 🙂

3 Replies


TSH is suppressed but FT3 is low in range. Most people on T3 only need FT3 higher > 5.0 to feel well. FT4 is below range because you are taking T3 only.

Did urticaria and angiodema develop after you started taking Liothyronine? They can be rare side effects of Liothyronine AND Levothyroxine:


Hi Clutter,

Thanks for your reply.

I started getting the urticaria last December.

Ive been on the liothyronine for about 7 years, (Levothyroxine for 12 years before) and never had problems but had a very bad year starting last May 2015.

I had a seizure, then a suspected seizure/syncope/blackout (not diagnosed) in August with a suspected heart attack which was diagnosed as myocarditis. Then the Urticaria started in December.

Im currently waiting to see a rheumatologist for RA, RF came back negative, but CRP results were 36.

Ive got a lot going on and seem to be going round in circles. Im trying to understand all blood tests and keeping copies but I don't know how to interpret the results.

My GP wants to take me off T3 and start over on T4 to see if this stops the urticaria. I will try anything to see if it helps, but when I was on T4 it never really made me feel better.

Sorry for the long post.

Jay-Jay :)



Try negotiating a resumption of T3 or T3+T4 if you don't feel well on Levothyroxine and if it doesn't improve urticaria and angioedema.

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