The pulmonary function laboratory in the investigation of dyspnea of unknown origin

Abstract

Chronic dyspnea (i.e., dyspnea for at least 3 months) negatively impacts the health-related quality of life of ~10% of the general population. In a sizable fraction of these individuals, the underlying cause remains unclear after detailed clinical assessment, basic pulmonary function tests, and chest imaging, characterizing dyspnea of unknown origin (DUO). The “lung doctor” is frequently called to assess these patients for diagnostic clarification, an endeavor fraught with complexities in most circumstances.