Chronic Obstructive Pulmonary Disease (COPD) is defined as a disease state characterized by the presence of airflow obstruction due to chronic bronchitis or emphysema. The airflow obstruction is generally progressive, may be accompanied by airway hyper-reactivity, and may be partially reversible. Inflammation in the lungs is triggered by exposure to inhaled toxic substances that can lead to tissue damage, mucous secretion, airways narrowing and tissue destruction.