Okay so here is my story. Since about six years ago I smoked marijuana and all of a sudden I had one I could see was a panic attack. I felt like I couldn't breeze my head was spinning and my heart was beating really fast and hard. Ever since that day I've had constant palpitations, and extremely tight feeling in my chest, not being able to breathe properly well feeling as if I can't breathe properly, sort of impending doom feeling, completely anxious, diarrhoea, and this inability to not know one am full up or when I've eaten enuff. Ever since that day I can know longer tolerate the things are used to do. I cannot tolerate smoking previous to that attack I could smoke as much as I wanted but now I can't. Two years ago I stopped smoking to alleviate these problems but it's been nothing but worse I constantly suffer from chest pains dizziness lightheadedness feeling of being spaced out anxious more than often. The tests I have done are ECG, EKG, chest x-ray, thyroid test, Spirometrey, stool sample, various blood tests, 24 hr holter moniter, eye check, blood pressure but they have found nothing. All I want to know is why I kept constant palpitations which seem to get really worse by exercising or doing strenuous activity. Stopping smoking has made this considerably worse and it's been two years ice I've seen a reduction in a few symptoms , but does anyone know why I keep having palpitations it's stopping me from doing everything. I really have any other symptoms apart from the palpitations which are very scary as they can come out of nowhere and last the whole day