Chronic obstructive pulmonary disease (COPD) is a chronic, non-curable, progressive illness that results in the obstruction of airflow in the lungs due to damaged lung parenchyma. COPD is an umbrella term that refers to lung diseases such as emphysema and chronic bronchitis. Emphysema causes the alveoli in the lungs to progressively become destroyed and lose their elasticity, therefore resulting in shortness of breath. Chronic bronchitis causes inflammation and irritation of the bronchi in the lungs, leading to the increased production of mucus. The most common cause of COPD is smoking, and it most commonly affects people who are heavy smokers and in their late 30s or older. Worldwide, 210 million people have been diagnosed with COPD; in 2005, 3 million people died from the disease, and it is predicted that by 2030, COPD will become the third leading cause of death in the world (WHO, 2008).