A 61-year-old man with a history of limited prostate cancer and osteoarthritis but no significant cardiopulmonary disease was evaluated for daytime and nighttime hypoxia. The patient moved from sea level to 2,500 m (8,200 feet) approximately 3 years prior to evaluation. During a routine physician visit, the patient was noted to have a history of snoring and witnessed apneas that occurred primarily during sinus infections. He otherwise denied significant daytime somnolence, dyspnea, cough, or exercise intolerance and enjoyed skiing at high altitude without difficulty. He denied taking any medications, including sedative-hypnotic agents or narcotics.