The document discusses bronchiectasis, which is a disease characterized by permanent dilation of the bronchi and bronchioles caused by destruction of muscle and elastic tissue. It can be congenital or post-infectious. Morphologically, the bronchi and bronchioles are dilated up to 4 times normal size. Histologically, the walls show inflammation and fibrosis. Clinically, it presents with persistent cough and sputum. Complications include lung abscess, amyloidosis, and cor pulmonale.