Likely Etiologies of Cough Based on Duration Acute(<3 weeks) Acute viral upper respiratory tract infection(common cold Subacute (3-8 weeks) Post-viral(post-infectious Bordetella pertussis(whooping cough) Chronic(8 weeks )* Upper airway cough syndrome(postnasal drip syndrome; rhinitis Conditions associated with eosinophilic airway inflammation Asthma Non-asthmatic eosinophilic bronchitis Gastroesophageal reflux disease(GERD) Acid reflux Non-acid, or weakly-acid, reflux Occupational/ Environmental Unexplained in patients who are not smokers, have no active pulmonary disease evident on radiographic imaging, and not currently receiving angiotensin converting-enzyme(ACE)inhibitors Current Opinion in Pharmacology Clinical perspective cough an unmet need. t)in Phhendbbl2015Tun: 22: 24-8Clinical perspective - cough: an unmet need. Curr Opin Pharmacol. 2015 Jun;22:24-8