Obstructive sleep apnea (OSA)is an often under-diagnosed disorder, characterised by periods of apnea and/or hypopnea that occurs during sleep. Emerging evidence shows that it is strongly associated with cardiovascular disease. In this book, the authors present current research in the study of the causes, treatment and health implications of OSA. Topics include the risk factors and interventions for non-adherence to CPAP; the benefits of CPAP therapy; a discussion on whether primary snoring is a benign symptom of OSA?; mechanisms underlying endothelial dysfunction in OSA; and the efficacy of intraoral devices for OSA.