I have had about 3 occasions where I have had really bad chest pains over the past year or so. The 'episodes' normally last for about 10 mins and I feel like I have a crushing pain in my chest which won't go away. The last one I had a pain in the middle of my back as well - between shoulder blades. I am currently on thyroxine and one of the side effects is supposed to be chest pains. Has anyone been affected similarly or know what it might be. I am afraid I am going to suffer a heart attack !