Obstructive sleep apnea (OSA) has many consequences. There is an independent association between OSA and hypertension. The Sleep Heart Health Study reported that hypertension prevalence increased as sleep disordered breathing severity increased. The Nurses' Health Study noted an age-adjusted relative risk of cardiovascular events of 1.46 for occasional snorers and 2.02 for regular snorers, and a risk of stroke of 1.60 for occasional snorers and 1.88 for regular snorers. Sleep apnea is also associated with pulmonary hypertension, neurocognitive effects, depressed quality of life, motor vehicle accidents, awakening headache, childhood growth interruption, pregnancy-induced hypertension, fetal growth retardation, and disruption of the patients' bed-partners' sleep quality. Further research will examine the possibility of causality, pathophysiologic mechanisms, and outcomes of therapeutic interventions for OSA on the many consequences of OSA.