Does anyone on here have an underactive thyroid? I went to the dr. a month ago for blood tests for feeling ill all of the time. I thought it would come back overactive if anything because i was having those symptoms. I am quite surprised it came back underactive. He said it was only slightly abnormal and i have to have another test in a month to see where to go from there. Thing is i've heard bad things about the tablets they put you on - that they make you gain alot of weight and make loosing weight almost impossible. Does anyone have any experience of this?