A tracheostomy creates a direct opening into the trachea below the larynx (typically between the 2nd and 3rd tracheal rings), bypassing the upper airway's natural warming, humidifying, and filtering functions. The tracheal mucosa has pseudostratified ciliated columnar epithelium with goblet cells that produce mucus for trapping particles. When bypassed by a tracheostomy, inspired air reaches the lower airways cold, dry, and unfiltered, causing increased mucus production, impaired mucociliary clearance, and mucus plug formation risk. The cuffed tracheostomy tube creates a seal against the tracheal wall, preventing aspiration and allowing positive pressure ventilation. Over-inflation of the cuff (>25 cmH2O) causes tracheal mucosal ischemia, leading to tracheomalacia, tracheal stenosis, or tracheo-innominate fistula (rare but fatal hemorrhage from erosion into the innominate artery). Proper cuff pressure management (20-25 cmH2O) balances aspiration prevention with mucosal preservation.