OSA

Obstructive Sleep Apnea (OSA) arises from a collapse of the pharyngeal airway during sleep, often due to a combination of anatomical factors (e.g., enlarged tonsils, retrognathia, obesity, soft palate) and neuromuscular changes that reduce muscle tone in the upper airway during sleep. This collapse leads to a complete cessation of airflow (apnea) or a significant reduction (hypopnea) for periods typically lasting 10 seconds or longer. Each event often concludes with a brief arousal from sleep, often unnoticed by the individual but disrupting sleep architecture. Common symptoms include loud, habitual snoring, witnessed breathing pauses, gasping or choking during sleep, excessive daytime sleepiness, morning headaches, irritability, and impaired concentration. Diagnosis of OSA primarily relies on polysomnography (PSG), a sleep study that monitors various physiological parameters during sleep, including brain activity, eye movements, muscle activity, heart rhythm, airflow, and blood oxygen levels. Home sleep apnea tests (HSATs) are also increasingly used for diagnosis in appropriate patients. Severity is typically categorized by the Apnea-Hypopnea Index (AHI), which measures the average number of apneas and hypopneas per hour of sleep. An AHI of 5-15 events/hour usually indicates mild OSA, 15-30 events/hour moderate, and >30 events/hour severe OSA. Other important metrics include oxygen desaturation index (ODI) and sleep architecture disruption. Untreated OSA poses substantial long-term health risks. It is a major independent risk factor for hypertension, coronary artery disease, stroke, atrial fibrillation, heart failure, and insulin resistance, increasing the risk of type 2 diabetes. Neurocognitive deficits, such as impaired memory, attention, and executive function, are also common. Treatment aims to restore normal breathing during sleep and alleviate symptoms. The primary treatment is Continuous Positive Airway Pressure (CPAP), which uses a mask to deliver pressurized air, keeping the airway open. Other treatment options include oral appliances, positional therapy, lifestyle modifications (weight loss, avoiding alcohol and sedatives), and, in some cases, surgical interventions targeting airway obstructions (e.g., uvulopalatopharyngoplasty, genioglossus advancement, bariatric surgery). Consistent adherence to treatment is crucial for mitigating health risks and improving quality of life.