Table 1. Principal causes of coughs.

Cough type		Possible causes
Acute cough	Dry	Viral infection Contact with an allergen Inhalation of a foreign particle Inhalation of irritant gases or powders Rarely even partial spontaneous pneumothorax or small pulmonary embolism
	Productive	Bacterial infection COPD exacerbation Less typically an attack of bronchial asthma Rarely acute left ventricular failure with pulmonary edema or arteria pulmonalis embolism
Chronic cough	Dry	Inhalation of pollutants Chronically foreign particles Bronchial asthma Rhinitis, postnasal drip syndrome Gastroesophageal reflux Cough after infection Carcinoma including metastases ACE inhibitor therapy Habitual cough
	Productive	Chronic bronchitis Chronic obstructive pulmonary disease (COPD) Bronchiectasis Cystic fibrosis Some infections (tuberculosis, pulmonary mycosis)