Breathlessness is the subjective (undue) awareness of breathing, breathlessness inappropriate to the level of physical exertion or even occurring at rest is termed dyspnea. Dyspnea has been more specifically defined by the American Thoracic Society as the "subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity ". The experience derives from interactions among multiple physiological , psychological, social and environmental factors, and may induce secondary physiological and behavioral responses. Objective measurement of dyspnea is therefore difficult .
It may be qualified by asking how many stairs can be climbed without stopping. The classification of Roizen has 5 grades of dyspnea (vide infra). Undiagnosed dyspnea of grade 2 or worse may require further investigation. The classification given by the medical research…
