Crackles are often associated with inflammation or infection of the small bronchi, bronchioles, and alveoli. Crackles that don't clear after a cough may indicate pulmonary edema or fluid in the alveoli due to heart failure or adult respiratory distress syndrome (ARDS).

Do crackles indicate pneumonia?

For example, crackles that occur late in the inspiratory phase (when a person inhales) may indicate heart failure or pneumonia.

What do rales indicate?

Crackles (Rales)

Crackles are also known as alveolar rales and are the sounds heard in a lung field that has fluid in the small airways. The sound crackles create are fine, short, high-pitched, intermittently crackling sounds. The cause of crackles can be from air passing through fluid, pus or mucus.