Understanding the foundations of chronic cough.

Despite chronic cough being one of the most frequent reasons for both primary care and specialty physician visits, its diagnosis and treatment remain challenging. The most common causes are upper airway cough syndrome, asthma, and gastroesophageal reflux disease; however, new research has implicated a cough hypersensitivity syndrome that may link many underlying etiologies. To accurately diagnose and treat patients with chronic cough, a thorough understanding of the various definitions, epidemiology, and pathophysiology is crucial. This article reviews these factors as well as the healthcare and socioeconomic burden of chronic cough.