Anatomical Basis of Obstructive Sleep Apnoea: A Review of Randomized Controlled Trials.

Repeated obstruction and closure of the upper airway, sporadic hypoxic episodes, and sympathetic activity are symptoms of obstructive sleep apnea (OSA). Obstructive sleep apnoea is due to a combination of altered upper airway structure and muscular function, a low arousal threshold and increased loop gain. Although recurrent upper airway (UA) collapse during sleep is the most frequent clinical hallmark of OSA, the exact cause of this collapse is unknown.