The absence of dyspnoea, cough and wheezing: a reason for undiagnosed airflow obstruction?

Objectives: The diagnosis of obstructive lung disease (OLD) may be overlooked because of the poor correlation between the intensity of symptoms and the severity of airway obstruction (AO). Undiagnosed airflow obstruction (UDAO) is associated with health impairment and mortality. Questions remain such as the reasons for its occurrence and the underlying diseases.