Emphysema is a lung disease that involves damage to the air sacs (alveoli) in the lungs.

Cigarette smoking is the most common cause of emphysema. Tobacco smoke and other pollutants are thought to cause the release of chemicals from within the lungs that damage the walls of the air sacs. This damage becomes worse over time. Persons with this disease have air sacs in the lungs that are unable to fill with fresh air. This affects the oxygen supply to the body.

A naturally occurring substance in the lungs called alpha-1 antitrypsin may protect against this damage. People with alpha-1 antitrypsin deficiency are at an increased risk for this disease.

• Shortness of breath
• Chronic cough with or without sputum production
• Wheezing
• Decreased ability to exercise

• Anxiety
• Unintentional weight loss
• Ankle, feet, and leg swelling
• Fatigue

A physical examination may show wheezing, decreased breath sounds, or prolonged exhalation (exhalation takes more than twice as long as inspiration). The chest may be barrel-shaped. There may be signs of chronically insufficient oxygen levels in the blood.

These tests help confirm the diagnosis:

• Pulmonary function tests
• Chest x-ray
• Arterial blood gases showing low levels of oxygen in the blood (hypoxemia), and high levels of carbon dioxide (respiratory acidosis)

This disease may also alter the results of the following tests:

• Pulmonary ventilation/perfusion scan
• Chest CT scan

Smoking cessation is the most important and effective treatment. Only quitting smoking can stop the progression of lung damage once it has started. Medications used to improve breathing include bronchodilators, diuretics, and corticosteroids. Antibiotics may be prescribed when respiratory infections occur. Vaccines against the flu and pneumonia are recommended for people with emphysema.

Low-flow oxygen can be used during exertion, continuously, or at night. Pulmonary rehabilitation can improve exercise tolerance and quality of life in the short-term. Lung transplantation is an option for patients with severe disease.

Carefully selected patients may be eligible for lung reduction surgery. This procedure removes the damaged portions of the lung, which allows the normal portions of the lung to expand more fully and take advantage of increased aeration. When successful, those who undergo the surgery report improvement in walking distance and quality of life.

Visit the American Lung Association's web site at www.lungusa.org to find a support group near you.

The outcome is better for patients with less damage to the lung. Prognosis is largely determined by initial shortness of breath, exercise tolerance, and results from lung function tests (spirometry). Death may occur from respiratory failure, pneumonia, or other complications.

• Recurrent respiratory infections
• Pulmonary hypertension
• Cor pulmonale (enlargement and strain on the right side of the heart)
• Erythrocytosis (increased red blood cell count)
• Death

Call your health care provider if you develop symptoms of emphysema.

If you know you have emphysema, call your health care provider if breathing difficulty, cough, sputum production or fever develops or changes.

Avoiding smoking -- or quitting if you do smoke -- can greatly decrease risk for this disease.