Chronic obstructive pulmonary disease (COPD) is a chronic, progressive lung disorder characterized by persistent airflow limitation that is not fully reversible. It develops gradually, most often due to long term exposure to harmful E cigarette use tied to increased COPD, asthma risk MDedge Association of electronic cigarette use and risk of COPD: a systematic review and meta analysis npj Primary Care Respiratory Medicine COPD What Smoking is Really Doing to Your Lungs ABILITY Magazine COPD is a progressive, largely irreversible airflow limitation characterized by chronic cough, sputum production, and dyspneamost commonly due to smoking. Spirometry (FEV FVC < 0.7) confirms diagnosis; smoking cessation is the most effective COPD (Emphysema and Chronic Bronchitis): From Diagnosis to Treatment Manual of Medicine