ABSTRACT
Stridor is a harsh noise produced by obstruction to breathing in the larynx or trachea. Inspiratory stridor usually predominates, but obstruction in the subglottic area or trachea may also produce a soft expiratory stridor. Stridor may arise from an acute condition, or from a chronic persistent cause with recurrent symptoms. The site of the obstruction may be supraglottic, glottic or subglottic (tracheal).
