In trying to explain to many patients about their lung disease I am often confronted by misunderstandings patients have about chronic obstructive pulmonary disease (COPD) and the term emphysema. Many times patients will ask if they have COPD or emphysema. COPD encompasses patients with chronic airflow obstruction and patients with emphysema (which is a destruction of lung tissue). Recently, researchers have been looking at which is most important in determining the relationship of airflow obstruction and lung destruction. Not surprisingly, airflow obstruction is the harbinger of lung tissue destruction. Patients were tested to look for early airway obstruction in the smaller airways, 2 millimeters or less in size.
In the development of COPD early airway obstruction accounts for the majority of disease, but as time moves on lung tissue destruction becomes more apparent. When emphysema occurs the airways lose the small, microscopic, elastic fibers that help to keep our small airways open. This leads to the collapse of these airways and worsening airflow obstruction. We also know that in smokers with mild airflow obstruction the rate of progression of that obstruction is greatest in the early stages of their disease. This tells us that the primary problem early on in COPD is the airway obstruction and limitation to flow that is the primary issue and that emphysema is really the end result of this progressive airway obstruction or what I like to call “the finished product of the cigarette roller’s art”.
