My feet & ankles are swollen, hot and reddish color. I have high blood pressure, lupus, asthma, back problems, diabetic, fibromyalgia, and Padgett disease, an enlarged heart, and enlarged thymus gland.
1 Free T4 (Free Thyroxine) â considered a precursor hormone, T4 is converted to T3 as required by cells throughout the body; levels of T4 are generally much higher than T3.  Total T4 (Total Thyroxine) - Most T4 in the blood is bound to carrier proteins which make it biologically inactive. Total T4 includes unbound (free) T4 plus T4 that is bound to carrier proteins in the blood.
Each carrier protein has a specific role. The sequence of the chains of amino acids defines the specific shape and function of the protein. Each carrier protein accepts only one molecule. The molecule is attached to the carrier protein, and the carrier changes shape moving the molecule into the cell.