Hi Pete! I know how difficult it is to have difficulties to breathe! I have astma when I get a cold. It is called cold astma or something. Exercising and medicine have keept it in shape really well. If I eat something that gives me difficulties to breathe, it starts within half an hour from the time I was eating. Maybe it helps you a little. Or it is stress, and it starts when you are trying to relax and your body gets stressed out off it. If you understand what I mean. hugs Lotta (used to be Sandra)