RespiratoryPending review

Obstructive Sleep Apnoea

Loss of upper airway muscle tone during sleep allows soft tissue (worsened by obesity and anatomical crowding) to collapse the pharynx, causing repeated episodes of partial or complete airway obstruction that fragment sleep and cause intermittent hypoxia, so the daytime and cardiovascular consequences all trace back to sleep that is never allowed to become restorative.

In a nutshell

Sleep-related loss of pharyngeal muscle tone allows a narrowed airway (from obesity or anatomical crowding) to collapse repeatedly, causing hypoxia and cortical arousals that fragment sleep without fully waking the patient. Daytime sleepiness, morning headache and resistant hypertension all trace back to this obstruct-arouse-reopen cycle repeating throughout the night.

Classic presentation

An obese adult with loud snoring, partner-witnessed apnoeas or choking arousals, excessive daytime sleepiness and morning headache.

Key points

  • The pharynx has no rigid support and depends on muscle tone to stay open; normal sleep-related relaxation is enough to collapse an already-narrowed airway.

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Educational content pending clinical review. Not medical advice.