Respiratory sensations in asthma: Physiological and clinical implications

Dyspnea is a cardinal symptom of asthma and may arise from several pathophy siological mechanisms, including pulmonary hyperinflation, stimulation of v agal receptors, and, rarely, chemoreceptor stimulation. The language that p atients use to describe their breathlessness may provide important clues ab out the physiology underlying symptoms in a particular,, Patient. Several p hysiological derangements may contribute to dyspnea in a given individual. The variability in the severity, of breathlessness for any given degree of airflow obstruction may relate to differences in the relative importance of these physiological changes and/or to a range of perceptual abilities in a sthmatic patients. One hypothesis that is under current investigation is th at defective perception of asthma symptoms may lead to undertreatment and t he potential for greater morbidity and mortality from asthma.