Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term used to describe obstructive lung diseases including emphysema, chronic bronchitis, refractory asthma, and some forms of bronchiectasis. This disease is characterized by shortness of breath and cough with sputum production. Emphysema is a common type of COPD that primarily causes shortness of breath due to over- inflation of the air sacs in the lung. Damage in this area makes it problematic for people with emphysema to expel air from their lungs. This leads to a build-up of carbon dioxide in the body and a countless number of emphysema signs and symptoms. Chronic Bronchitis causes irritation and inflammation of the bronchial tubes, the airway that carry air to lungs. When the air tubes are inflamed and irritated, thick mucus starts forming in tubes. Over time, this mucus plugs up airways and difficulty in breath starts. When you cough this mucus up, the discharges are known as sputum, or phlegm. Asthma COPD Overlap Syndrome (ACOS) occurs when eosinophilic bronchial and systemic inflammation, reversible airflow obstruction, and increased response to inhaled corticosteroids, compared with COPD patients. Wheezing, coughing, chest tightness and shortness of breath are some of the symptoms.