What is the most common cause of bronchiectasis?

Bronchiectasis is a condition characterized by the abnormal and permanent dilation of the bronchi, often resulting from chronic inflammation and infection. The most common cause, as indicated in the selected answer, is chronic infections associated with poor mucus clearance. Conditions that impair the clearance of mucus can lead to the accumulation of secretions in the airways, predisposing individuals to recurrent infections. These infections then perpetuate the cycle of inflammation and damage to the bronchial walls, which ultimately leads to bronchiectasis.

In clinical practice, situations such as cystic fibrosis, bronchial obstruction, or even severe asthma can lead to compromised mucus clearance and are commonly associated with bronchiectasis. Other forms of respiratory disease that involve repeated inflammation of the airways can similarly result in bronchiectasis due to the recurrent cycle of infection and inflammation.

While genetic disorders and environmental pollutants can play a role in the pathogenesis of bronchiectasis, they are not as prevalent or direct as chronic infections arising from inadequate mucus clearance. These other factors do contribute to the overall risk but are not the most prevalent causes. Therefore, chronic infections with poor mucus clearance is the predominant mechanism leading to bronchiectasis in the majority of cases.