Vocal cord dysfunction.

Vocal cord dysfunction (VCD), generally characterized by paradoxical closure of the vocal cords during inspiration, is a common mimicker of asthma and of other conditions that cause upper airway obstruction. As a result, it is frequently overlooked and often misdiagnosed, resulting in administration of excessive medications or other unnecessary interventions, with resultant morbidity. This article explores the clinical features, proposed causes, diagnostic considerations, and management of VCD, as well as some differences between VCD and asthma that can aid in differentiating these two diagnoses in the clinical setting.