What respiratory sound is characterized by a harsh or high-pitched noise due to upper airway obstruction?

The sound characterized by a harsh or high-pitched noise due to upper airway obstruction is known as stridor. This respiratory sound typically occurs when there is a blockage in the upper airways, such as from swelling (e.g., due to an allergic reaction), foreign bodies, or infections. Stridor can be a sign of a serious medical condition requiring immediate attention, as it indicates that airflow is being hindered and the patient may be in respiratory distress.

In contrast, wheezing is a high-pitched whistling sound that occurs primarily in the lower airways due to constriction or inflammation, commonly seen in conditions like asthma or COPD. Rhonchi are often described as snoring or gurgling sounds associated with mucus buildup in the larger air passages, typically heard in conditions like bronchitis. Crackles, also known as rales, indicate fluid in the alveoli, often associated with conditions such as pneumonia or heart failure. Each of these sounds reflects different underlying respiratory issues, emphasizing the importance of accurately identifying stridor as an indicator of upper airway obstruction.