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Obstructive sleep apnea — USMLE Step 3 MCQ

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EasyAmbulatory Medicine / Primary CareObstructive sleep apneaUSMLE Step 3

A 35-year-old man with obesity has loud snoring, morning headaches, and daytime sleepiness. Polysomnography shows recurrent apneic episodes with oxygen desaturation. Blood pressure is 148/88 mm Hg. Which of the following is the most likely explanation for this patient's findings?

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Correct answer: D — Recurrent upper airway collapse during sleep

Obstructive sleep apnea is caused by recurrent upper airway collapse during sleep, producing intermittent hypoxemia and sympathetic activation.

Reference: AASM sleep apnea guidance; USMLE Step 3 Content Outline