Obstructive sleep apnea.

Obstructive sleep apnea is diagnosed with the use of polysomnography by documenting repetitive periods of upper airway closure during sleep. Apneic episodes can compromise gas exchange and disrupt the sleep pattern. The challenge to the clinician is to suspect this diagnosis when evaluating the awake patient. The history of loud snoring plus daytime hypersomnolence or multiple awakenings during sleep justifies ordering a polysomnogram. The importance of diagnosing obstructive sleep apnea is underscored by the resolution of its sequelae with effective medical or surgical treatment.