How is Obstructive Sleep Apnea defined?

Obstructive Sleep Apnea (OSA) is specifically characterized by repeated episodes of airway obstruction during sleep. This condition occurs when the muscles in the throat relax excessively, leading to a blockage in the upper airway. These episodes can result in interrupted breathing, which often leads to arousals from sleep, poor sleep quality, and can contribute to various health issues such as cardiovascular disease, hypertension, and daytime fatigue. The obstructive nature of the apnea is crucial—it signifies that the cessation of breathing is due to a physical blockage rather than a failure of the respiratory center in the brain, which distinguishes it from other respiratory conditions.

The other options do not accurately describe the primary characteristics of Obstructive Sleep Apnea. Chronic sinusitis is associated with nasal obstruction and inflammation but does not specifically relate to the episodes of airway obstruction during sleep. An inability to breathe due to muscle fatigue could refer to other respiratory disorders but does not encapsulate the mechanism of airway obstruction that defines OSA. Periodic leg movements during sleep are related to a separate condition known as periodic limb movement disorder, which is distinct from the airway obstructions typical of obstructive sleep apnea.