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How does obstructive sleep apnea disrupt breathing and sleep?

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Obstructive sleep apnea (OSA) is a respiratory condition characterized by the physical collapse of tissues in the upper airway during sleep. This blockage prevents normal airflow, leading to a reduction in oxygen levels in the blood.12

The disruption to sleep occurs because these airway obstructions are typically terminated by a brief, involuntary arousal or awakening. Once the person awakens, the airway reopens, allowing breathing to resume—often accompanied by a gasp or snort. Because these episodes can occur repeatedly throughout the night—sometimes as often as once every minute in severe cases—the individual's sleep is fragmented and of poor quality.12

This cycle of obstruction and arousal prevents the patient from achieving restorative rest, commonly resulting in excessive daytime sleepiness, difficulty concentrating, and irritability. While often associated with obesity and excess neck fat, the condition can also stem from anatomical factors like enlarged tonsils or discoordinated activity of the muscles surrounding the upper airway.12