In acute cough, the most common causes are Upper respiratory infection (URI), including acute bronchitis Postnasal drip Pneumonia In chronic cough, the most common causes are Chronic bronchitis Postnasal drip Airway hyperresponsiveness after resolution of a viral or bacterial respiratory infection (ie, postinfection cough) Gastroesophageal reflux COPD (chronic obstructive pulmonary disease) The causes of cough in children are similar to those in adults, but asthma and foreign body aspiration may be more common in children.