Title says it all. I have been told by at least two gp doctors that I have a perfectly working thyroid. It turns out that my t4 is 0.9, which according to various internet resources is really low, because the normal range starts at 4.5. Is it possible that the lab my doctors use is different, and .9 is normal? On Monday I will have my bloodwork faxed to me, but assuming that is the case, can you tell me what you know about t4? Thanks!