Bronchiectasis is a chronic lung condition characterized by abnormal dilation of the bronchi and bronchioles. It can be caused by airway obstruction, infections, genetic disorders like cystic fibrosis, or immunodeficiencies. Symptoms include chronic cough, excessive sputum production, recurring lung infections, shortness of breath, and finger clubbing. Diagnosis involves chest imaging, sputum analysis, and pulmonary function tests. Treatment focuses on airway clearance techniques, antibiotics for infections, and sometimes surgery to remove diseased portions of the lung.