This document discusses obstructive sleep apnea (OSA). It begins with a case study of a 67-year-old man presenting with snoring and daytime sleepiness. It then defines OSA and discusses its pathophysiology and risk factors. The approach to diagnosis involves taking a history, physical exam, and polysomnography. Treatment options include behavioral modifications, oral appliances, continuous positive airway pressure (CPAP), and various surgical procedures. CPAP is the gold standard treatment and can provide numerous health benefits by improving sleep quality and cardiovascular and metabolic outcomes.