Bronchi are the airways or breathing tubes in the lungs. Bronchiectasis is an irreversible widening (dilation) of portions of the bronchi resulting from damage to the airway wall. Which of the following is the most common cause of bronchiectasis?
Cystic fibrosis
Immunodeficiency disorders
Inhalation of toxic substances such as noxious fumes, gases or smoke
Severe or repeated respiratory infections
