title: Sleep apnea and its causes.
mesh_terms: D000402:Airway Obstruction / Q000503:physiopathology; D000818:Animals; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology; D012016:Reference Values; D012119:Respiration; D012891:Sleep Apnea Syndromes / Q000209:etiology / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology