Upper airway resistance syndrome

The upper airway resistance syndrome describes a constellation of symptoms, namely, fatigue and excessive daytime sleepiness, attributable to polysomnographic findings of prolonged inspiratory flow limitation and repeated arousals from sleep due to increased upper airway resistive events that do not meet the criteria for apneas or hypopneas. While now subsumed under the diagnosis of obstructive sleep apnea as a clinical entity, the term remains in use in the sleep medicine community necessitating that practitioners of sleep medicine be familiar with it. This chapter uses a representative case to discuss the history, epidemiology, polysomnographic findings, and treatment approach for this often misunderstood syndrome.