Serum free T4 level

[foxglove]

Is T4 same as FT4?

[diogenes Remembering]

No. T4 is all the thyroxine circulating in blood. Nearly all of it is bound on to proteins that carry it through the blood to where it is needed. FT4 is the very small amount that is freed from the proteins when they pass the tissues, to allow the tissues to take up the T4 they individually need for health.

[foxglove in reply to diogenes]

Thanks for reply.

[Hidden in reply to foxglove]

T4 = Total T4

FT4 = Free T4

as diogenes explanation above.

thyroid.org/wp-content/uplo...

[foxglove in reply to Hidden]

Thanks for reply and link- much obliged.