It's good that you have the FT3 and FT4 test results. Along with symptoms, those are the best indicators of thyroid state. In my opinion the very best way to treat a thyroid patient is to test and adjust FT3 and FT4 levels with whatever med is required to alleviate symptoms. Symptoms are what it should be all about, not just getting test results somewhere within the reference ranges, so that the doctor thinks results are okay.
We hear from many members that they continue to suffer from hypo symptoms when their FT3 and FT4 levels are within the reference ranges, but in the lower part of the range. My assessment of why this is the case is as follows.
The reason the reference range for TSH is called "normal", is that it's based on a large population of patients' test results. From that data base the decision was made that about 5 % of people would fall out of this "normal" range because they were possibly hypo or hyper. From this decision limits were placed at plus and minus two standard deviations (which places 2.5% of the results outside each limit) from the overall average and that was called the "normal" range, supposedly representing people who had no thyroid problems.
After many years of bad experience with this "normal" range for TSH, it was finally acknowledged 6 years ago that there were a lot more patients out there with hypo and hyper problems than previously accepted when they originally used their data base to establish the range.
After excluding from the data base those patients who were suspect for hypo and hyper, they again analyzed the remaining data base and established limits that included 95% of the total data base and called these new limits "normal". This changed the reference range from .5-5.0 down to .3-3.0, which is a huge change. Unfortunately this change hasn't yet been accepted or acknowledged by most labs and doctors, even though the change was recommended by the AACE over 6 years ago.
Also, realize that the reference ranges for the "Frees" were established the same basic way. These ranges have never been reexamined and modified like the range for TSH. I am absolutely convinced that this is the reason why so many hypo people fall into the lower end of the ranges for FT3 and FT4 and are still told they are "normal".
In one my past lives I had a lot of training and experience in statistical analysis. Based on that experience, if I had to estimate what a revised range for FT3 would be if the data base were purged of suspect hypo and hyper people, like was done for TSH,then I would say the FT3 range should change from 2.3-4.2 pg/dl up to about 3.2-4.3. And FT4 probably would change from .60-1.50ng/dl up to about 1.0-1.55. Quite a difference, huh? Think maybe that is why we hear from so many people that have hypo symptoms, yet they are in the "normal" ranges for the "Frees"? I'd bet my last dollar.
If your doctor thinks your test results are perfect, then you are going to have to use info like this to change his mind and increase your meds to get your FT3 and FT4 higher within the reference range.
by the way, my free T3 is 2.54
what is the range of the free T3? I have the same kind of story, been on Synthroid for years, but still feel hypo even though my TSH is ok. Well, my free T3 is still low so I had my dr add Cytomel (T3) to Synthroid. Feeling better so far!
Yeah...I guess it would have helped if I posted my results!!! (still dealing with "brain fog")
TSH 1.560
free T3 2.4
free T4 .86
please post your numbers and the reference ranges,