Obstructive sleep apnea

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction of the upper airway leading to reduced or absent breathing during sleep. These episodes are termed "apneas" with complete or near-complete cessation of breathing, or "hypopneas" when the reduction in breathing is partial. In either case, a fall in blood oxygen saturation, a disruption in sleep, or both, may result. A high frequency of apneas or hypopneas during sleep may interfere with the quality of sleep, which - in combination with disturbances in blood oxygenation - is thought to contribute to negative consequences to health and quality of life. The terms obstructive sleep apnea syndrome (OSAS) or obstructive sleep apnea–hypopnea syndrome (OSAHS) may be used to refer to OSA when it is associated with symptoms during the daytime (e.g. excessive daytime sleepiness, decreased cognitive function). Most individuals with obstructive sleep apnea are unaware of disturbances in breathing while sleeping, even after awakening. A bed partner or family member may observe a person snoring or appear to stop breathing, gasp, or choke while sleeping. People who live or sleep alone are often unaware of the condition. Symptoms may be present for years or even decades without identification, during which time the person may become conditioned to the daytime sleepiness, headaches and fatigue associated with significant levels of sleep disturbance. Obstructive sleep apnea has been associated with neurocognitive morbidity and there is a link between snoring and neurocognitive disorders. In the third edition of the International Classification of Sleep Disorders (ICSD-3), obstructive sleep apnea is classified amongst the sleep-related breathing disorders and is divided in two categories, namely adult OSA and pediatric OSA. Obstructive sleep apnea is differentiated from central sleep apnea (CSA), which is characterized by episodes of reduction or cessation in breathing attributable to decreased effort, rather than upper airway obstruction.