The respiratory tract epithelium plays a major role in the interface between inhaled toxins and the host system. Impairment in the epithelial lining clearance capacity and/or a disturbance in its microbial environment can result in an imbalance in homeostasis. Numerous studies indicate that e-cigarette smoking leads to injury to the mucosal lining of the upper respiratory tract and impairs its function. As such, e-cigarette users often complain of an array of respiratory symptoms such as cough, excess mucus, and dyspnea, with exacerbation of lower airway diseases. The respiratory symptoms in e-cigarette users are attributed to changes in bronchial epithelia, including an increase in inflammatory biomarkers, cellular toxicity, and apoptosis, all of which increase the risk of respiratory infection.