Thyroid test question

[ollyma28]

I have been taking  100mgc of synthroid for years.  I recently had a TSH and Free T4 blood test.  My TSH was 0.18 and the Free T4 was 1.2.  My doctor wants to change my synthroid to 88MGC.  Am I within normal range or does this mean I am low or hyperthroid? I am 65 years old.

[ollyma28]

I don't think he did  a FT-3.  Don't see anything like that on my report.  Would these lab results be the reason I have lost weight the past few months?  I am down 30 lbs.  Glad I am, but not if it is because something is wrong.  I have to have blood work again in six weeks so will take your suggestion and ask for a FT3 as well.  What do you mean it will bring the FT4 down?  What will that do?  What needs to be done so that doesn't happen?  

[GravesLady]

Yes, your TSH is on the low side and warrants lower med. dose. Looks like your
FT-4 is on the low side as well.  Did doctor do a FT-3?  Something else might be going on, but can't surmise with out knowing FT-3 too.  Nothing serious, maybe thyroid/adrenal related.

When  your TSH level goes up from the med. dose change, it will bring down the FT-4  level, you don't want yours much too lower.

When you go for retest in 6 weeks from starting new dose, ask doctor to do all three levels - TSH,
FT-4 and FT-3.

The older we get the less thyroid hormone we need.