Posted by Larry Hoover on February 6, 2006, at 13:50:12
In reply to thyroid tests, posted by Shelley on January 24, 2006, at 12:31:48
> Hi everyone,
>
> I suspect having suffered from hypothyroidism for several years but TSH is normal. If I can only do one other test to determine if there is a hidden problem, what should it be- free T3? Total T3?
> Something else? Assuming T4 turns into T3, am I right in assuming that testing only T4 would not be the right choice?
>
> Thanks.You are right, but many doctors assume that testing T4 and TSH is all you really need to know. Even what represents normal in TSH values is under a lot of scrutiny. The normal threshold is dropping, as doctors slowly smarten up.
Hidden thyroid problems require a panel of simultaneous tests.
You'd want, in addition to free and total T4 and TSH, but also free and total T3, T3 resin uptake (to compute FTI, also called T7), and tests for thyroid antibodies (evidence for Hashimoto's thyroiditis).
Some labs use resin uptake to compute free T3 and T4, whereas others use separate assays. There may be some overlap in what I recommended, but maybe not. Your doctor would know.
Getting your doctor to do those tests is the hard part. With normal TSH, it might be harder still.
Lar
poster:Larry Hoover
thread:602360
URL: http://www.dr-bob.org/babble/health/20060202/msgs/606915.html