Smoking, atmospheric pollution, and some genetic conditions can damage the delicate walls of the millions of tiny air sacs in the lung. The sacs become larger spaces that are less efficient as their walls are destroyed. The walls of the air sacs are where the oxygen in the air enters the blood, and the carbon dioxide in the blood enters the air and can then be exhaled. Breathlessness results from complex effects on lung function and airflow in the airways.
Emphysema cannot be reversed once it has developed. Treatment is usually targeted at COPD if it is present with emphysema. Occasionally endobronchial valves or coils, or surgery can be useful in reducing breathlessness due to emphysema itself. Sometimes a large area without air sacs develops called a bulla and, in certain circumstances, surgery can be helpful for this too. CT scanning is useful if further information about emphysema and bullae is needed to guide management.