Question: What Causes Chronic Obstructive Pulmonary Disease (COPD)? Dr. David Sanderson: The principle cause of chronic obstructive pulmonary disease really is well known to be cigarette smoking and cigarette smoking indeed is probably the leading preventable cause of disease in this country, not only lung disease, but heart and cardiovascular disease as well, but particularly individuals who have smoked for a long period of time are very likely to develop chronic bronchitis and that is one of the elements within the umbrella of chronic obstructive pulmonary disease.