Abnormal expansion of bronchi in the lungs. It usually results when preexisting lung disease causes bronchial inflammation and obstruction. Bronchial wall fibres degenerate, and bronchi become dilated or paralyzed, preventing removal of secretions, which stagnate. Infection spreads and intensifies. Evidence of the disease includes presence of infective agents, excess mucous secretions, and, in children, fatigue and growth retardation. Complications include recurrent pneumonia, lung abscesses, spitting up blood, and, in chronic cases, toe and finger clubbing. Treatment involves frequent, long-term drainage or (if the disease is on one side only) surgical removal of affected lung segments and antibiotics.