COPD Symptoms: Top Warning Signs, Chronic Bronchitis, Emphysema and Asthma Symptoms in COPD

9. Prolonged expiration

People with COPD have more air inside the lungs than they can handle. Their inspiration volume decreases, and they tend to prolong their expiration volume. The respiratory cycle is the same in mild and moderate COPD, but the latter has more predominantly prolonged expiration. Inspiration, expiration, residual volume, and other measures can be taken by spirometry.