Thyroid UK

Could I please have some help understanding my blood results? - especially FT3

Starting levo but decided before starting that I wanted to see what my FT3 was like and whilst I was at it to see if I had both thyroid antibodies. So had BH home blood tests.

Here are the results:

TOTAL THYROXINE(T4) 103 nmol/L (59 - 154 )


FREE THYROXINE 16.1 pmol/l (12.0 - 22.0 )

FREE T3 4.8 pmol/L (3.1 - 6.8)


Thyroglobulin Antibody *179.0 IU/mL ( 0-115)

Method used for Anti-Tg: Roche Modular

Thyroid Peroxidase Antibodies*184.3 IU/mL (0 - 34)

To compare with my previous results that have different ranges:


08/13 1.4 (0.35-5.5)

01/14 3.4 (0.35-5.5)

03/14 2.4 (0.35-5.5)


08/13 16.4 (10-19.8)

01/14 13.3 (10.19.8)

03/14 14.7 (10-19.8)


09/13 92(0-100)

01/14 247(0-100)

0/3/14 1229 (0-100)

So I now know I have both antibodies which is neither here nor there as I know now I am dealing with autoimmune disorder,

I know that my tsh is totally unreliable. From what has been explained to me with the different lab ranges I take it that a result of 3.78 with the range of 0.27 to 4.2 isn't the same as a range that my gp's lab uses (0.35-5.5) so had I had it done with my gp at the same time I would have had a different number...higher I expect. Should I just be disregarding TSH anyway because of the autoimmune problem which is obviously making it go up and down like a yo-yo eventhough still in range?

FT4 isn't super low but it would be better if it was higher.

Now FT3 is new to me and don't really understand it. Am I in right in assuming that low FT3 means conversion problem and what you are aiming for is a nice high FT3? Is mine ok? It's just under the half way point so does it mean I'm converting fine?

I also know that you are meant to do a ratio of some sort between FT4 and FT3, how do I do that?

4 Replies

Just to confirm - the BH results are BEFORE you started the levo...?

Yes - generally, people need a FT3 towards the top end of the reference range.

How much levo are you starting on..?




Hi louise,thanks for replying. That is correct, tests from midweek,started 25mcg levo this morning.


Thanks. :)

Let us know how you get on! :)

Are you taking it with water only, at least 30 mins to 1 hour before eating..? Just checking... :)




looks as though you are starting to get things under control....... that's gr8! the antibodies will take a bit longer

to pipe down but looking good ....


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