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.
thyroxine-binding globulin (TBG), a plasma protein that binds with and transports thyroxine in the blood. A gene on chromosome Xq22.2 that encodes thyroxine-binding globulin (TBG), the major thyroid hormone transport protein, which is genomicallyâbut not functionallyârelated to the serpin family.hyronine-binding globulin (TBG) (thyroxine-binding globulin) an acidic glycoprotein that is the main binding protein in the blood for thyroxine, and less firmly for triiodothyronine.