Hi everyone...I have just been diagnosed with an under active thyroid which I have suspected for the last 5 years, I started taking the 25mg he prescribed last Wednesday in the morning and left it an hour before I had anything to eat. I felt a little strange but nothing too bad. But I'm Friday night about 1.30am I was just getting into bed and I suddenly went really hot and my heart started racing but not just fast it was beating irregularly..I also had a shaky internal feeling and felt extremely hyper. It frightened the life out of me and was worried about going back to sleep. I eventually dozed off but was woken up again a couple of hours later with similar symptoms. I decided to go to our local urgent care centre and saw a doctor there who said he thought that I had a reaction to the thyroxine. He told me just to take one pill every other day...but I decided to take half every day. I still have the shaky feeling but my heart is not irregular at the min. Am I abnormal or had anyone else experienced this please. should I keep taking the thyroxine or should I stop and see my gp again?