4 years on and join the club on tiredness. I have an idea mine is depression though and when it isn't that it is my irregular heart beat which usually doesn't worry me but when its every 3 or 4 beats then a backwards beat it makes me very lethargic and tired. I am on medication to stop the heart racing but there doesn't seem to be anything they can do for the short in the heart I have. I got it after a reaction to chemo and just have to live with it as ultrasounds of the heart didn't find a reason for it.