How To Determine Whether The Conversion Of T4 To T3 Is Proper?

Hello: For years I had suspected, based on empirical evidence, that I had an issue with my thyroid. Got tested a couple of years ago and everything was fine with TSH, Free T3 and Free T4. Started researching, went back and asked my doc to run them again as well as Rev T3, Iodine, TPO and TgAB. Results were as follows: Free T3 = 2.5 (ref 2.3 - 4.2) Free T4 = 1.2 (ref .8 - 1.8) TSH = 1.15 (ref .4 - 4.5) Rev T3 = 10 (ref 8 - 25) TPO = TgAB = 16 (ref So while all of my other numbers are normal the TgAB shows some inflammation of the thyroid. 16 is not horrible but may explain my low basal temp, brittle nails, dry skin, dry hair, slow metabolism, etc. So this is all very new to me. My questions are this: How does one determine if the T4 is not adequately converting to T3? Doc started me on 50 mcg Synthroid (brand name only) but how do I know if my T4 adequately converts to T3? If it doesn t then just a t4 med isn t going to help. Second question is, how does one determine Hashi s vs. plain hypo? Thank you.