Obstructive sleep apnea (OSA) may be associated with myriad clinical consequences such as increased risk of systemic hypertension, coronary vascular disease, congestive heart failure, cerebrovascular disease, glucose intolerance, impotence, obesity, pulmonary hypertension, gastroesophageal reflux, and impaired concentration. Nonetheless, OSA remains undiagnosed in 82% of men and 93% of women with the condition. Early identification and treatment of OSA provides significant relief for individuals, prevents complications of OSA, and reduces overall health care costs. Better understanding of the pathogenesis, risk factors, diagnosis, and treatment of OSA has the potential to improve early recognition of OSA and prevention of adverse effects on the individual and society.