COPD exacerbations often lead to a downward spiral of physical activity. To compensate for the discomfort brought on by exertional dyspnea and the accompanying fatigue, patients with COPD will settle into a sedentary lifestyle that deconditions their bodies, serves to further aggravate breathlessness, and results in a further downward adjustment of physical activity. Progression of COPD imposes profound limitation on activities of daily living and gives rise to anxiety and depression. The distressing symptoms of breathlessness and the perception of these abnormalities by the patient lead to a reduction in health-related quality of life. The clinician's therapeutic interventions have to address these symptom and activity limitations with the goal of improving the patient's quality of life.