Acute bronchitis is usually caused by a virus, while the chronic form is due to inhalative noxae (in most cases decades of cigarette smoking). Both varieties are diagnosed on a clinical basis. Treatment of acute bronchitis is symptomatic. A sore throat is treated locally, and a troublesome, in particular nocturnal, cough with antitussive agents applied for a limited period (14 days). If bronchial mucus is viscous and difficult to clear, short-term treatment with a secretolytic or mucolytic substance is justified. Management of chronic bronchitis consists primarily in the elimination of the noxae. Treatment with antibiotics (usually oral) makes good sense only when there is a bacteriological infection of the upper or lower airways in an acute stage, such as infection-driven exacerbation of chronic obstructive bronchitis (COPD).