I have been on thyroid medicine ( armour thyroid ) 1 gr since around July 1, 2012 as prior tests & symptoms; such as tiredness, loss of concentration, feeling cold, constipation, loss of eyebrows, depression and extreme hair loss , indicated an underactive thyroid ( hypothyroid ). As of Dec. 14, 2012 more lab work indicated that & it has shifted to an overactive thyroid ( hyperthyroid ). Why then do I seem to have all of the symptoms still of an underactive thyroid?