Thanks for the replies, I appreciate it. It will be interesting to know what my GP says. I don't want to worry about it until I know for sure. I agree that Pericarditis is the closest explanation but I'm not totally convinced because I don't get chest pains, and I would have thought that my doctor would have noticed this in the past whenever he's used a stethoscope on me in the past? Also, this has been happening for years! I didn't realise that this was a rare thing, I just assumed everyone's heart squeaked?!