high t4 and normal ft4

[venkatramanb]

MY blood report says total thyroxine t4 as11.6 mg/dl , which is almost nearer to the upperlimit of ref range, and the free t4, as only, 1.14ng/dl, which iis not even at the middle of the ref range 0.7-1.8ng/dl.and the tsh , as 10.69, which shows my thyroxine supplimentation, daily, 25mcg.as inadaquate.The total thyroxine level is very good at the upper limit of range, means my thyroid gland is alright working., but still high tsh. I am 70yrs old.shall I increase suplimentation, to reduce tsh.

[Barb135]

venkatramanb... Total T4 is considered to be an outdated test as it shows both the bound and unbound (Free) T4 in your blood.  Most T4 is bound by a protein and can't be used. We're concerned with the Free portion of the T4, because that's what available to be converted to the usable hormone, T3.  Like T4, much of the T3 in your blood is bound by a protein and can't be used... you should also have had a Free T3 test, since Free T3 is the hormone used by individual cells in your body.

Your Free T4 is only at 40% of its range and the recommendation is for Free T4 to be around mid range; therefore, I would suggest a small increase in your medication.  The increase is to relieve symptoms, if you  have any, not just to decrease TSH, since TSH does nothing but stimulate the thyroid and if your thyroid isn't working, TSH is only an indicator.  Talk to your doctor about the amount of increase in medication.  Perhaps you can tolerate 50 mcg/day or perhaps you might need to alternate 25 mcg and 50 mcg for an average of 37.5 mcg/day.  It depends on what you and your doctor agree upon.  As we get older, we often have to increase our dosages much slower than when we're younger.

Next time you get tests, get Free T3, along with the Free T4 and TSH; don't worry about the Total T4, since it really tells you nothing.