Cardiology Patient Page. Obstructive Sleep Apnea.

Abstract

Obstructive sleep apnea (OSA) is a common sleep disorder that affects 2% to 7% of the population. It is a serious medical condition that has many effects on health, happiness, and survival, beyond simple snoring and poor sleep. OSA often goes undiagnosed, and many patients with risk factors for OSA should be evaluated for the disease. OSA is initiated by inappropriate closure of the upper airway during sleep, leading to a cessation in breathing that is often terminated by a gasp and awakening (see Figure). Patients with OSA are prone to airway closure for a number of reasons. First, they have a smaller airway opening than those without OSA. They also have changes in the muscles surrounding the airway that make it more collapsible than normal. People who are obese or have a large neck circumference are at particular risk of airway closure because of the excess tissue that may compress the airway opening further. When awake, patients with OSA are able to keep the collapsible airway open, but when they are asleep, the airway muscles relax, putting the patient at risk of airway closure. Figure. Pathophysiological mechanisms of OSA. This is a schematic of the mechanism responsible for OSA. (1) The patient begins awake, and as he/she falls asleep, the upper airway tissues relax and start to close. (2) Once asleep, the airway closes completely. As a result, breathing stops. (3) When the patient’s oxygen levels fall and carbon dioxide levels rise, he/she is stimulated to breath. This stimulation results in awakening, in addition to gasping and rapid …