Fig. 3:  This presentation begins with some take-home points.  Number one, dyspnea is typically the overriding symptom in advanced COPD.  Certainly fatigue and cough, as well as other factors and variables are present, but dyspnea is by far the most important symptom.  Dyspnea has multiple causes and physiologic underpinnings.  Dyspnea can be quantified in COPD, which is important in defining the severity of this disease, both clinically and for large clinical trials, and dyspnea in COPD is profoundly related to hyperinflation.