My breathing is heavy even when I am not doing anything much and have not done much in over an hour. Every website I go to says that I have some sort of serious medical condition but they all have a lot of other symptoms and I m not experiencing any symptoms besides the heavy breathing. I have never been the most athletic person but I am reasonably healthy for my age and while this may not be very severe at the moment I am getting a bit concerned as it has been going on for a couple of weeks now.