What do rales indicate in a patient's lungs?

Rales, also known as crackles, are abnormal lung sounds that generally indicate the presence of fluid in the airways or alveoli. When a clinician hears rales during a physical examination, it often suggests conditions associated with congestion in the lungs, such as pneumonia, heart failure, or pulmonary edema. The characteristic wet crackling sound that is produced is a direct result of the movement of air through fluid-filled passages. Therefore, when rales are present, it is typically an indicator of a pathological process occurring within the lungs, such as an infection or significant inflammation, making the association with pneumonia particularly relevant. This connection highlights the importance of rales as a diagnostic clue in assessing pulmonary health.