Common Abnormal Sounds
Wheezing is a high-pitched whistling sound caused by narrowed small airways, as seen in asthma. Crackles (rales) are fine popping sounds from fluid in the alveoli, as in pulmonary edema or pneumonia. Rhonchi are low-pitched rattling sounds from mucus in larger airways. Stridor is a harsh, high-pitched sound from upper airway obstruction.
Where to Listen
Auscultate at the midaxillary and midclavicular lines, comparing both sides. Listen at the apices and bases. In trauma, listen for absent or diminished sounds, which may indicate a pneumothorax or hemothorax.
Clinical Meaning
Stridor is an emergency requiring immediate attention, especially in children, because it indicates a significantly narrowed airway. A silent chest in a distressed patient may signal severe obstruction. Always correlate sounds with the patient's overall condition.