Chronic Obstructive Pulmonary Disease (COPD) is a preventable, diagnosable but incurable group of lung diseases. This group of lung diseases is characterized by increase in resistance to airflow caused by partial or complete obstruction at any level hence the irreversible airflow obstruction. The diseases included in COPD are • Emphysema • Chronic bronchitis • Bronchiectasis In COPD, Forced Vital Capacity (FVC) = normal or slightly decreased Forced expiratory volume at 1 second (FEV1) = decreased FEV1 : FVC = decreased