Emphysema is another form of chronic obstructive pulmonary disease. It is a serious respiratory disease. The most common cause of disease is smoking. Cigarette smoking causes damage to the air sacs in the lungs. The air sacs become stretched and damage occurs. The person suffering from emphysema has trouble in exhaling air from their lungs. This results in a chronic cough and difficulty breathing. This type of respiratory illness leads to respiratory failure and the need for extra oxygen to meet breathing needs. Emphysema evolves very slowly from months to years. Symptoms of emphysema include shortness of breath especially during light exercise, wheezing, ongoing fatigue, long term cough or smoker cough, large mucus production. Treatment includes stopping smoking and taking medicines. Bronchodilators and sometimes corticosteroids are recommended in the treatment of emphysema. Oxygen therapy is recommended in those with low oxygen levels at rest.