The reason why patients with COPD feel subjective dyspnea
is a simple question. However, answering this
question is not simple, and clinicians need to understand
the mechanisms responsible for dyspnea. It is
widely accepted that the major limitation to exercise
performance and the perception of breathlessness in
COPD can be attributed to dynamic hyperinflation,
although activity limitation and dyspnea in COPD is
multifactorial.