Obstructive sleep apnea should be suspected in patients who are overweight snore loudly, and have chronic daytime sleepiness. The diagnosis of sleep apnea may be confirmed by sleep laboratory studies. Patients' symptoms and the frequency of respiratory events on laboratory testing are important factors in determining the severity of disease. In patients with mild sleep apnea, conservative treatment measures include getting sufficient sleep, abstaining from the use of alcohol and sedatives, losing weight, and avoiding the supine position during sleep. Continuous positive airway pressure (CPAP) is the most consistently effective treatment for clinically significant obstructive sleep apnea. In general, heavier patients with thicker necks require higher pressure settings. As patients age or gain weight, additional pressure may be necessary. Bilevel pressure machines or machines that slowly ramp up the pressure may increase patient acceptance of CPAP therapy. Complications of CPAP use include nasal dryness and congestion, claustrophobia, facial skin abrasions, air leaks, and conjunctivitis. Strategies to improve patient compliance include allowing patients to try a number of masks to find the most comfortable fit, adding humidification, treating nasal disease and, most importantly, providing close follow-up and encouragement. Oral appliances are inconsistently effective in the management of obstructive sleep apnea but may be an option in patients with mild disease who cannot tolerate CPAP. Palatal surgery often decreases snoring but may not reduce the occurrence of sleep apnea. Patients with severe disease and intolerance of CPAP may be candidates for more invasive surgical procedures. Supplemental oxygen and drug therapy may have limited, adjunctive roles in the treatment of obstructive sleep apnea.