Blood test

[Dave583]

Typical reference ranges for normal thyroids (uk guide)

Test From To Units

TSH

0.4 4.0mU/L (milliunits per litre)

FT4

9.0 25.0 pmol/L (picomoles per litre)

FT3

3.5 7.8pmol/L (picomoles per litre)

My levels on 100mcg Levothyroxine.

TSH 0.02

FT4 100

FT3 24.1

Stopped meds 5 weeks ago. Recent uptake scan - no traced identified

[helvella Administrator Thyroid UK]

With thyroid hormone levels that high, it is a miracle you have any detectable TSH.

I note you had a sub-total thyroidectomy and take 100 micrograms of levothyroxine.

Why did you have that sub-total thyroidectomy?

I really don't think I'd take any levothyroxine tomorrow if those were my results.

How are you feeling?

[Dave583 in reply to helvella]

I had a sub total thyroidectomy as I had graves disease. I feel fine. No symptoms of an overactive thyroid. But I did have shingles 12 weeks ago.

[helvella Administrator Thyroid UK in reply to Dave583]

I suspect those test results are not reflecting your true thyroid hormone levels. Quite a number of things can interfere with these tests - one that has been mentioned here many times recently is biotin.

I have no idea if shingles could have any impact - either way. Have you been taking any medicines or supplements?

[helvella Administrator Thyroid UK in reply to helvella]

There is at least a suggestion of an association between shingles and a history of thyroid disorders:

ncbi.nlm.nih.gov/pubmed/261...

[Dave583 in reply to helvella]

Thanks for the information

[Dave583 in reply to helvella]

No nothing at all. I 've taken the same amount of levothyroxine for 25 years and no problems. It's the second blood test in 5 weeks the only difference in the readings was that the last blood test my t4 level was 116

[helvella Administrator Thyroid UK in reply to Dave583]

I suggest that a repeat test should be done by a different lab, one that uses a different technology for performing the tests. You'd need to discuss this with your doctor or choose to get a private test done. (Contact the company to make sure that you are sure any test is done with different technology.)

That can help to identify interference (though not the cause).

[Dave583 in reply to helvella]

Ok will talk to GP. Thanks for advice