<em>Asthma and COPD are both chronic lung diseases. COPD is mainly due to damage caused by smoking, while asthma is due to an inflammatory reaction. COPD is a progressive disease, while allergic reactions of asthma can be reversible.</em><em>With asthma, the swelling is often triggered by something you're allergic to, like pollen or mold, or by physical activity. COPD is the name given to a group of lung diseases that include emphysema and chronic bronchitis. Emphysema happens when the tiny sacs in your lungs (called alveoli) are damaged</em><em>.</em>