Someone already posted it... there are several things that happen when switching from smoking to vaping (I still have a friend that I'm trying to convert but she says vaping makes her cough (or could it be the cigs and blame it on vaping) It's a transition thing (believe me, and I have been back an forth between vaping that I love, and smoking that I hate but still do) there is no doubt that vaping is so much better (after 8 months just vaping, my doctor told me my lungs were great even oxygen reading was really good) Now I have slipped back into dual use and hate myself (still love vaping more so determined to quit the natsties) I remember those days (switching) and it is confusing, but I can tell you my lungs felt so mush better, I didn't miss the nasty smell, my doc used to say my lungs are fine and now here I am dual using (long story...) It's worth it... stay with it. I'm afraid to to go back to the doc... he might tell me my lungs are F*t. Sorry... not the best pep talk but real... do anything to stay off the smokes.