Clarifying Terminology in Chronic Cough: The Evolving Role of Cough Hypersensitivity Syndrome.

Chronic cough is defined as a cough lasting no less than 8 weeks, and 10%-42% of patients with chronic cough retain their cough after comprehensive examination and treatment. The terms idiopathic chronic cough (ICC), unexplained chronic cough (UCC), and refractory chronic cough (RCC) are frequently used to describe this clinical condition. However, these terms are often used interchangeably in articles, leading to heterogeneity in the populations included in the studies and compromising the value of the findings in guiding clinical practice. This article aims to clarify the current terminological confusion by reviewing the definitions and relationships among ICC, UCC, and RCC in the literature, and to discuss the emerging role of cough hypersensitivity syndrome (CHS) as an important pathophysiological framework for understanding chronic cough, with a focus on its clinical value, current challenges, and future perspectives.