Thyroid testing

[gimel]

I'm fully aware of the six year old recommended revision to the reference range for the pituitary hormone, TSH.  From what I have read it was revised to reflect the fact that there existed a much larger percentage of hypo and hyper patients than originally thought when the old range was established.  After purging from the data base those suspect patients, the range changed significantly down to .3-3.0.   I'm concerned that the reference ranges for the biologically active thyroid hormones that correlate best with symptoms (FT3 and FT4) have never been revised, consistent with the TSH change.  So it seems to me that FT3 and FT4 ranges still include a lot of test data from hypo and hyper patients and therefore, should not really be considered as "normal" .  It seems logical to me that this is why we hear from so many long suffering patients on the thyroid forum who still have hypo symptoms, yet are told they are "normal", and need no more medication because their FT3 and FT4 results are within the low limit of the ranges.  Instead of these ranges being interpreted as guidelines within which to adjust FT3 and FT4 as necessary to alleviate symptoms, results within the low limits are interpreted as being adequate.  Would appreciate comments as to why these ranges have not been revised like TSH, which my background in statistical analysis says would put them at 3.2-4.3 pg/ml for FT3 and 1.0-1.55 ng/dl for FT4.   Thank you.

[gimel]

When you said that "This is being worked on", I was not sure if you meant that you were working on an answer to my questions, or if the FT3/FT4 range problems are being worked on.  ??????

[Mark Lupo, M.D.]

This is being worked on.