Chronic Obstructive Pulmonary Disease is a progressive disease that causes airflow blockage and problems related to breathing. It can cause coughing that produces large amounts of a slimy substance called mucus, wheezing, shortness of breath as well as chest tightness. Cigarette smoking is the leading cause of COPD. Long-term exposure to various lung irritants such as air pollution, chemical fumes, or dusts also contribute to COPD. A rare genetic condition called alpha-1 antitrypsin (AAT) deficiency can also lead to COPD. COPD cannot be cured but it can be treated to lower the chance of complications, and generally improve quality of life. Clinical symptoms and signs, such as abnormal shortness of breath and increased forced expiratory time, can be used to help with the diagnosis of COPD. Various forms of treatment include Medications, supplemental oxygen therapy and surgery.