I quit all nicotine for 6 months, then was smoking a pack or two a week for maybe two months before going back to vaping fairly heavily a couple of weeks ago. In the last week or so I have been getting short of breath easily and chest pain when I walk, it seems to be worse when I am vaping very heavily. At the doctor's office today my oxygen was a bit low, it was 94% whereas usually it is around 98% (below 95% is considered unhealthy). The nurse just asked if I have been dizzy or lightheaded lately, I told her no. I'm a little worried about my lungs. I don't know whether to go to the emergency room (I had pulmonary embolism a few years ago that felt kind of similar) or cut back/stop vaping and see what happens. Input, anyone? Has anyone heard of something like this happening from vaping?