Pathophysiology of upper airway obstruction during sleep.

Obstructive sleep apnea is a common medical disorder with significant adverse health consequences. The pathogenesis of pharyngeal obstruction during sleep, however, remains elusive. This article addresses the key mechanisms of upper airway (UA) obstruction including the role of transmural pressure, pharyngeal compliance, pharyngeal dilating muscle activity and non-neuromuscular factors. A proposed scheme of the pathophysiology of UA obstruction is outlined.