When crackles, wheezes, or rhonchi clear with a cough, which of the following is a likely etiology?

When crackles, wheezes, or rhonchi clear with a cough, the etiology is often related to bronchitis. In cases of bronchitis, the airways become inflamed and produce excessive mucus, leading to the presence of these abnormal lung sounds. When a patient coughs, the mucus can be mobilized and expelled, which often results in the clearing of these sounds during auscultation.

This phenomenon indicates that the underlying issue is primarily related to mucus accumulation within the airways rather than a structural or more fixed lung pathology. Other conditions such as pneumonia, asthma, and COPD may involve similar lung sounds, but they often have different underlying mechanisms or fixed obstructive components that do not resolve simply with coughing. In pneumonia, for example, the sounds may persist due to consolidation of lung tissue, while in asthma and COPD, there tends to be more chronic airway obstruction that is not resolved through coughing.