Vaping refers to the act of inhaling and exhaling aerosol, often called vapor, produced by an electronic cigarette or similar device. These devices heat a liquid that usually contains nicotine, flavorings, and What Does Vaping Do to Your Lungs? Johns Hopkins Medicine Impact of e cigarette vaping on the immune system across the body Physiological Reviews American Physiological Society Flavor induced inflammation and cytotoxicity in human aortic smooth muscle cells: Potential implications for E cigarette safety ScienceDirect