COPD What Smoking is Really Doing to Your Lungs ABILITY Magazine Association of electronic cigarette use and risk of COPD: a systematic review and meta analysis npj Primary Care Respiratory Medicine 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 E cigarette use increases risk for developing major respiratory diseases