Emphysema is a lung disease that results from destruction of lung tissue and irreversible enlargement of the alveoli (air sacs) that deliver oxygen to and remove carbon dioxide from the blood.
As the walls of the alveoli become progressively enlarged, they lose elasticity and have a reduced ability to force air out of the lungs during expiration. As a result, the affected air sacs cannot properly fill up with fresh air during inspiration, and the exchange of oxygen and carbon dioxide between the alveoli and the blood becomes impaired. This leads to the shortness of breath that characterizes emphysema.
The onset of emphysema is gradual, with symptoms typically developing after age 50, however, irreversible lung damage may occur long before symptoms become severe enough to warrant medical attention. Such damage is initiated by smoking or other lung irritants, which lead to the destruction of lung tissue.
Like chronic bronchitis, emphysema is one of the primary lung disorders that constitutes chronic obstructive pulmonary disease, or COPD.
Symptoms of Emphysema
- Shortness of breath.
- Wheezing.
- Cough (wet or dry).
- Fatigue.
- Weight loss.
- Barrel-chested appearance.
What Causes Emphysema?
- Smoking is the leading cause of emphysema. Up to 85 percent of emphysema cases develop in longtime cigarette smokers.
- Prolonged exposure to lung irritants, such as industrial fumes and dust, and living in areas with poor air quality are other factors associated with the development of emphysema.
- Emphysema may also occur as a result of an inherited deficiency of alpha-1-antitrypsin (AAT). This enzyme normally hinders tissue destruction in the lung. Rare individuals missing this enzyme can develop emphysema at an early age, even if they don’t smoke.
Prevention of Emphysema
- The only way to prevent emphysema is to avoid cigarette smoking. While nearly all smokers suffer some lung damage, quitting smoking can prevent further lung deterioration.
Diagnosis of Emphysema
- Patient history and physical exam strongly suggest the diagnosis of emphysema.
- Pulmonary function tests that measure breathing capacity confirm the patient has decreased lung function.
- Arterial blood samples are taken to measure the amount of carbon dioxide and oxygen in the blood.
- A chest x-ray or CT (computed tomography) scan will likely be required to demonstrate the lung damage that distinguishes emphysema from other forms of lung disease.
- A blood test can identify those rare individuals with alpha-1-antitrypsin deficiency.
How To Treat Emphysema
- Quitting smoking is the only available treatment that helps slow the progression of the disease. (There is no cure for emphysema.) Other lung irritants, including secondhand smoke, aggravate symptoms and should be avoided whenever possible.
- Moderate aerobic activity helps prevent the decline in physical conditioning associated with emphysema, and may improve the capacity for exertion.
- Taking measures to prevent chest infections, such as frequent hand washing and pneumonia and influenza vaccinations, can reduce illness in patients with emphysema. Antibiotics are prescribed when a bacterial infection occurs.
- A bronchodilator—a class of medication that helps open the airways—may be prescribed to make breathing easier.
- A trial of oral or inhaled steroids may be prescribed if bronchodilator therapy proves unsuccessful. Only about 20 percent of patients benefit from steroid therapy so lung function should be monitored for signs of improvement. Steroids may be discontinued if there is no objective evidence of improvement.
- Supplemental oxygen helps prolong life in patients with reduced blood oxygen levels.
- Some patients may benefit from special exercises that train muscles used for breathing. A doctor or physical therapist can provide instructions on how to perform these exercises.
- In those with very advanced lung damage, a lung transplant may be advised. Another type of surgery, lung reduction surgery, may reduce shortness of breath and eliminate the need for oxygen in selected patients. However, this type of surgery is not widely available, and benefits only a limited number of patients with emphysema.
- In symptomatic AAT-deficient patients, replacement alpha-1-antitrypsin therapy, which involves a weekly intravenous infusion of AAT derived from human plasma, may slow down the progression of the disease.
When To Call A Doctor
- Call a doctor if you experienced worsening of shortness of breath or if symptoms of emphysema become more severe.
For more information on emphysema and related diseases, click on this link -- Johns Hopkins Health Alerts: Lung Diseases
