Impact of increased t3 dose on free t4

[bikebabe]

does anyone have an explanation for why my free t4 increases when I increase my tri-iodothyronine? Theoretically my congenital inherited pendreds condition and my thyroids lifelong inability to generate t4 itself should mean free t4 stays the same?

[greygoose]

You might get more help if you posted some blood test results showing the increase, etc. Or, link to another post that contains said results. It's impossible to say much without more information.

[bikebabe in reply to greygoose]

Hi grey goose - it was a general query about the mechanism by which this situation might happen. I am redoing bloods next week in preparation for an endocrinology appointment and will post if these are needed.