Smoking the most common cause of emphysema

Emphysema is defined as dilation of the ends of the airway in the lung. This dilation is permanent and occurs from the destruction of the lung tissue that is responsible for the exchange of oxygen and carbon dioxide. The destroyed areas of lung include the alvoeli. These are the tiny air sacs where the blood comes into close contact with the inhaled air and gas exchange occurs. To be effective, there needs to be a large amount of these alveoli.

With destruction, there is a loss of the amount of surfaces available for oxygen to enter and carbon dioxide to exit the bloodstream. Emphysema is one of the two main components of chronic obstructive pulmonary disease (COPD). The other is chronic bronchitis. Most people with COPD have a combination of both components. Smoking is the most common cause of emphysema. Other risks include second-hand smoke, air pollution, occupational gases and toxic fumes and exposure to cooking fire without proper ventilation.

There are inherited forms of emphysema that are made significantly worse by the exposure to cigarette smoke. Shortness of breath, worse with exertion, fatigue, cough, wheeze, chest tightness and recurrent respiratory infections are common symptoms of emphysema. A pulmonologist can diagnose emphysema based on a patient's history and physical exam. This is confirmed by breathing tests, known as pulmonary function tests.

These tests can show obstruction to the flow of air and demonstrate an enlargement in the volume of air in the lungs. There is no cure for emphysema. The lung tissue has already been destroyed. Stopping smoking is the most important intervention to prevent progression of the destruction. Inhalers can help open up the bronchial tubes and unload trapped air.

Acute infections must be treated early and aggressively to prevent worsening of the lung disease. Pulmonary rehabilitation programs can improve a patient's strength and ability to exercise. Ultimately, in patients with severe disease, a lung transplant evaluation should be undertaken.