My 8 year old son is recovering from Flu B and an asthma flare. He is currently being treated with 20mg of oral prednisone (as usual in these circumstances). However today (day 7 since onset of flu) he is extremely fatigued and complaining of foot pain. His sleeping heart rate is sitting at 52, pulse ox at 95%. For several months he has been experiencing an intolerance to cold, and terrible constipation, as well as anxiety, and mood swings. Both myself and his father are hypothyroid. Are these symptoms simply from recovering from the flu virus, or could it be hypothyroid at this early age?