Girlie said...
for you thyroid savvy members - What do you do when the TSH is too low...but the FT4 is in the middle of the range.
I mean low as in .03 (if I'm remembering correctly)
If he feels good....no issues?
edited to change the TSH and also where the FT4 is in the range.
I should really start a new thread...maybe tomorrow. and share more information
Girlie
There is really no such thing as a "too low" TSH despite what thyroid-clueless doctors might say.
TSH has no physiological implications whatsoever. Remember: TSH is a pituitary hormone - just like FSH (hormone measured to gauge possibility of menopause).
It's the amount of *thyroid* hormone that has physiological effects and those are measured by the FT4/FT3 levels.
A low TSH level is just that: a low TSH. It can be normal for the person, a result of pituitary dysfunction or perhaps infection and, yes, it *might* indicate hyperthyroidism.
As long as the FT4/FT3 levels are at healthy places, there is no concern. Healthy FT4/FT3 levels are usually around 75% of range or higherThis is where doctors often drop the ball - they get "stuck on TSH" (a very common cry on thyroid forums)
Please know that TSH fluctuates as much as 200% throughout the day in the body's attempts at maintaining stable FT4/FT3 levels. Yet another reason why TSH should not be used to judge thyroid status.
Just to show you how TSH tells us very little, here is the range of FT4/FT3 levels that keep me symptom-free along with my average TSH levels:
FT4 1.8 - 1.84 (range .82-1.77) Yes, I feel best with my FT4 slightly over-range (this is a common need)
FT3 3.8 - 4.2 (range 2.0-4.4)
TSH <.005 (yes, virtually undetectable) up to .007
I didn't bother listing the range for TSH because my lab has not updated their testing kits to reflect the AACE's 2002 suggestion that the range be lowered to .3 - 3.0 which is still too high.
Studies have shown that healthy people have TSH 1.0 or lower.
Just because a test like TSH is sensitive (has measured units into the thousandths) doesn't mean it's giving us the information we seek. This is yet another fact that doctors miss.