Emphysema is a disease of the lungs. It is one of the diseases that make up chronic obstructive pulmonary disease (COPD) which is a set of diseases where the flow of air in the lungs is obstructed. Emphysema is most often caused by smoking but can be caused by other diseases or have no known cause at all. It occurs when the very small air sacs (called the alveoli) at the ends of the airways in the lungs start to break down from many sacs to form much bigger sacs. The alveoli are the areas of the lung where oxygen and carbon dioxide are exchanged into and out of the blood. Emphysema makes it hard for people to blow air out of the lungs because air gets trapped inside the broken alveoli due to the collapse of the walls. There is no cure at the moment for emphysema but treatment includes stopping smoking and taking medicines. Sometimes small amounts of oxygen are given to the patient but large amounts can cause problems. Sometimes sections of the lungs can collapse causing a pneumothorax where the lung comes away from the walls of the chest. This is a medical emergency and needs the patient to go to a hospital's emergency department. Emphysema can often lead to the death of the patient.
People who suffer from emphysema may also have swollen legs and ankles. This is due to a build up of lymphatic fluid in the tissues (which also may happen in the lungs). This happens due to failure or the right side of the heart. Severe cases of emphysema require hospital treatment but there is little that can be done to help. The damage cannot be reversed. Large amounts of oxygen are not, and should not, be given because this can actually lead to the person to stop breathing. This is because a person with emphysema becomes used to having a high amount of carbon dioxide (CO2) in their blood and the body switches to using the amount of oxygen (O2). When this happens if a person gets too much oxygen the body slows down breathing and can even stop breathing altogether.