so i have been vaping on and off for a year, usually ill stop when i start to get pains in my upper body, almost feels as if i have a knot in a back muscle or a weird pain or flutter in my chest, i have seen multiple doctors and i keep checking out fine. anyone have any ideas what it could be?.. almost feels like gas, but it isn't... 70% PG 30% VG on current juice, and am trying 0 nic (LOL) to see if that makes a difference, but the odd pain still comes back.. doesn't hurt to the point where i am grabbing my chest or back, but is very uncomfortable