During assessment of a patient with respiratory distress, wheezing is heard on auscultation. This most likely indicates:

• A. fluid in the alveoli
• B. swelling of the upper airway
• C. a lower airway obstruction
• D. secretions in the airway

Answer: (C)

Wheezing signals partial obstruction in the lower airways, where the bronchioles are narrowed by bronchospasm, inflammation, or edema. The sound is a high-pitched musical whistling produced as air rushes through constricted passages, often best heard during expiration. This pattern points to lower airway obstruction such as bronchospasm or reactive airways disease. By contrast, fluid in the alveoli tends to produce crackles, upper airway swelling leads to stridor, and secretions generally cause rhonchi rather than a true wheeze. So the presence of wheezing in a distressed patient most strongly indicates lower airway obstruction.