Which term describes a high-pitched sound caused by upper airway obstruction?

• A. Wheezing
• B. Rales
• C. Stridor
• D. Crackles

Answer: (C)

When there is obstruction in the upper airway, airflow becomes turbulent as it passes through a narrowed passage, especially during inspiration, producing a high-pitched, harsh sound called stridor. This sound is often audible without a stethoscope and signals potential airway compromise, as seen with swelling from conditions like epiglottitis, croup, laryngeal edema from an allergic reaction, or a foreign body lodged at the glottis. By contrast, wheezing comes from the lower airways and sounds like a musical whistling on expiration due to bronchoconstriction or secretions in the bronchi. Crackles (rales) are crackling sounds from fluid or secretions in the alveoli, usually heard on inspiration. Stridor’s harsh, vibrating quality near the neck makes it the best descriptor for an upper airway obstruction, and it should prompt immediate airway assessment and protective measures, including high-flow oxygen and readiness for advanced airway management.