I have been using ecigs, nicotine/marlboro flavor for about 6 months. I am now having major breathing problems, i smoked analogs for 20 years. Ecigs helped me quit, but they are NOT good for u, i find it difficult to catch my breath, its the most frustrating and scary feeling, so ive dropped the vaping. I just quit ecigs today, so ill let u know how quitting affects my breathing in a week or so, I also want to see a doc to see if there may be a med reason for what im goin thru. So dont think ecigs are the answer, in my experience they are a good way to quit analogs but NOT an alternative. There needs to be scientific studies done on ecigs as they relate to lungs, because right now there is NO official info. Vapors beware!