Obstructive sleep apnea (OSA) is a disorder in which a person stops breathing during the night, perhaps hundreds of times. These gaps in breathing are called apneas, meaning absence of breath. A constricted or collapsed airway causes snoring and is usually accompanied by disturbed sleep, and daytime sleepiness. The damaging consequences to the health of patient can be many, not the least of which could be high blood pressure. People might not even know they have the condition.