Stridor is defined as:

Stridor is defined as:

• A. Rattling noise due to mucus
• B. Continuous high-pitched whistling sounds
• C. Harsh or high-pitched respiratory sound through obstructed upper airway caused by inflammation or obstruction
• D. Late inspiratory crackles

Answer: (C)

Stridor signals upper airway obstruction and is heard as a harsh, high-pitched sound as air moves through a narrowed larynx or trachea, typically during inspiration and often due to inflammation or physical narrowing. This matches the description of a harsh or high-pitched sound caused by obstruction in the upper airway. It can help to distinguish it from other breath sounds: a rattling noise from mucus is a lower, softer sound known as rhonchi; a continuous musical whistling sound is a wheeze usually from lower airway narrowing; late inspiratory crackles come from fluid or stiffness in the lungs rather than a narrowed upper airway.

Stridor signals upper airway obstruction and is heard as a harsh, high-pitched sound as air moves through a narrowed larynx or trachea, typically during inspiration and often due to inflammation or physical narrowing. This matches the description of a harsh or high-pitched sound caused by obstruction in the upper airway. It can help to distinguish it from other breath sounds: a rattling noise from mucus is a lower, softer sound known as rhonchi; a continuous musical whistling sound is a wheeze usually from lower airway narrowing; late inspiratory crackles come from fluid or stiffness in the lungs rather than a narrowed upper airway.