Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive upper airway collapse during sleep, leading to oxygen desaturation and disrupted sleep. Symptoms include snoring, witnessed apneas, and excessive daytime sleepiness. The pathogenesis involves various factors, including small upper airway lumen, unstable respiratory control, low arousal threshold, small lung volume, and dysfunctional upper airway dilator muscles. Risk factors include obesity, male sex, age, menopause, fluid retention, adenotonsillar hypertrophy, and smoking. OSA is associated with sleepiness, road traffic accidents, and systemic hypertension. Continuous positive airway pressure (CPAP) is the primary treatment, with adherence rates of 60-70%. Bi-level positive airway pressure or adaptive servo-ventilation can be used for CPAP intolerant patients. Other treatments include dental devices, surgery, and weight loss. OSA has been linked to cardiovascular, metabolic, and neurocognitive effects, but the relationship with hard cardiovascular outcomes remains unproven. Future treatments may target specific causes, and new strategies are being explored.Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive upper airway collapse during sleep, leading to oxygen desaturation and disrupted sleep. Symptoms include snoring, witnessed apneas, and excessive daytime sleepiness. The pathogenesis involves various factors, including small upper airway lumen, unstable respiratory control, low arousal threshold, small lung volume, and dysfunctional upper airway dilator muscles. Risk factors include obesity, male sex, age, menopause, fluid retention, adenotonsillar hypertrophy, and smoking. OSA is associated with sleepiness, road traffic accidents, and systemic hypertension. Continuous positive airway pressure (CPAP) is the primary treatment, with adherence rates of 60-70%. Bi-level positive airway pressure or adaptive servo-ventilation can be used for CPAP intolerant patients. Other treatments include dental devices, surgery, and weight loss. OSA has been linked to cardiovascular, metabolic, and neurocognitive effects, but the relationship with hard cardiovascular outcomes remains unproven. Future treatments may target specific causes, and new strategies are being explored.