How is it diagnosed |
The initial diagnosis tends to be "the normal things don't work, what's happening". If someone has a low but stable temperature (stability indicating that adrenals are behaving), iron labs at a satisfactory level, and a Free T3 (FT3) near the top of the range then they may well have a RT3 issue. Their temperature should be normal with the rest of the things right. It can be diagnosed accurately by the ratio of Free T3 to Reverse T3. Once they are in the right units (the units used by labs differ so some have an FT3 range of 230 to 450 whereas others might have a range of 2.5 to 4.5) then the ratio of Free T3 divided by reverse T3 should be 20 or greater. If it's less then that you have a RT3 problem. If it's vastly smaller or larget you may have to move the decimal point to get the units right. There are some worked examples here If you only have a T3 reading rather than a FT3 reading then the ratio of T3 to RT3 needs to be 10 or greater. |