I switched from smoking to dipping throughout my life. A few years ago, when I switched back to dipping again I started to get extreme tightness in my chest. It would last anywhere from 15 minutes to half an hour. When it would happen, I'd get a panic attack as well. Not being able to breath all the sudden is pretty scarey. I went to the docs after it happened a few times, and he said it was acid induced asthma. I never had asthma in my life. I didn't know it was the dip that was causing it either. A couple of months of dealing with it, my sister (who is a hypochondriac, and has probably googled every disease etc that there is lol) told me she thought the dip was causing it. I didn't think it was. But the next time it happened I tossed the dip, and bought some smokes. That was the last time it happened, until I started vaping. The same thing is happening in the evenings. Not every evening, and not near as bad. I don't even mind it. It's not that bad. I drink a bunch of water and that almost cures it. But I do think this is what's happening to a lot of vapors. I'm no doctor, but this is just my opinion. Also I think the reason it might have been happening when I was dipping is because I was always spitting, instead of swallowing. I have also read that vaping dries you out a lot. I dunno, but maybe there's a link.