Obstructive sleep apnea is a sleep disorder in which breathing is briefly and repeatedly interrupted during sleep. The “apnea” in sleep apnea refers to a breathing pause that lasts at least ten seconds. Obstructive sleep apnea occurs when the muscles in the back of the throat fail to keep the airway open, despite efforts to breathe. Another form of sleep apnea is central sleep apnea, in which the brain fails to properly control breathing during sleep. Obstructive sleep apnea is far more common than central sleep apnea.
These obstructive events usually result in measurable drops in blood oxygen saturation, which returns to baseline levels when the person’s breathing resumes. Episodes of OSA typically end with the person waking up briefly in order to reopen his or her airway.
People who have OSA snore loudly between episodes and can also gasp and/or choke. As a result of the pattern of airway obstruction and multiple arousals that occur during the night, people with OSA have sleep fragmentation and often experience excessive daytime sleepiness (EDS).