auscultation

Auscultation is the act of listening to the sounds the body makes — here, the sounds of breathing — usually with a stethoscope. It turns the chest into something you can read with your ears: air moving smoothly, air struggling through narrowed tubes, or the pops and rumbles of fluid and secretions.

To listen to the lungs, the clinician places the stethoscope at matching points on both sides of the chest, front and back, while the patient breathes through an open mouth. Normal breath sounds are soft and rustling over most of the lung, louder and more hollow over the large airways. The examiner judges whether the sounds are present and equal on both sides, whether they are reduced or absent in any area, and whether extra sounds — wheezes, crackles, rhonchi, or a leathery pleural rub — are added.

Reduced or absent breath sounds over part of the chest can mean air, fluid or solid tissue is blocking sound from reaching the surface, as in pneumothorax, pleural effusion or collapse. Auscultation is quick, harmless and repeatable, which makes it a cornerstone of the bedside examination, but its findings are interpreted alongside the rest of the examination and imaging rather than in isolation.