So this is more for my mother-in-law. She is a heavy smoker and due to health problems, she would really like to try to quit or at least have a less-chemically invasive way to smoke. She has tried my vapor and she seems to cough really bad. Not like I did when I first started, but she says it feels like her lungs are swimming. She does seem to catch bronchitis and pneumonia extremely easily and she thinks that her lungs just cant handle the water vapor for this reason. I talked to our local vape shop about it and he stated that she may need a pure PG or VG mix. Now forgive me as I am new and I don't know what the hell he was talking about, but I was curious if anyone could explain the different to me on here or if this has happened to someone on here and what you did to get past it. I understand that we should consult her doctor which we will be doing, but again just curious if it happened to anyone on here. Thanks in advance.