Encyclopedia Home / E / Emphysema - HealthCentral Encyclopedia


  • Definition

    In emphysema (from the Greek word for "inflation"), the walls of the alveoli (air sacs) in the lung are destroyed and lose elasticity (the ability to spring back to shape), hindering the outflow of air (from the sacs) when a person exhales. Emphysema frequently occurs together with chronic bronchitis, and together these two diseases are called chronic obstructive pulmonary disease (COPD).


    Emphysema is characterized by loss of the normal elasticity of the lung that helps to hold airways open. With progressive inelasticity of the lungs, the small airways collapse on expiration, making it impossible to fully exhale air.

    Our current understanding of emphysema is incomplete, but the best models theorize that there is a delicate balance between natural substances that fight disease but can also destroy lung tissue (enzymes called proteases) and other substances that prevent this destructive process (e.g., alpha1-antitrypsin). Some people are born with a deficiency in their ability to produce alpha1-antitrypsin, which makes it more likely that they will get emphysema at an earlier age. However, deficiency in alpha-1-antitrypsin accounts for only a small percentage of all people with emphysema.

    A major cause of both chronic bronchitis and emphysema is smoking. Emphysema may masquerade for years as something else. Frequently, people are told that they have “asthma” or “bronchitis.” A person with emphysema may have had several very bad colds each winter for a few years, each accompanied by a heavy cough and possibly chronic bronchitis. The cough often persists and becomes chronic.

    Emphysema develops slowly. Slight morning and evening difficulty in breathing may be followed sometime later with shortness of breath that interferes with normal activities. A short walk may be enough to bring on breathlessness and walking up stairs is difficult. Eventually, as the lungs become less and less able to carry out inhaling, exhaling and gas exchange, there may come a point when every breath requires a major effort and the patient is disabled and unable to carry out normal activities.

    Shortness of breath is the symptom that most commonly prompts a person to seek medical attention. The patient may mistake the problem for asthma or heart disease. In fact, emphysema may lead to serious cardiovascular problems. Because the disease interferes with the passage of blood through the lungs and into the circulation, the heart must work harder. It may enlarge and eventually lead to heart failure.


    Individuals who have emphysema often follow a pattern: they are primarily men, between the ages of 50 and 70 who have been heavy smokers for years. In the past, women did not develop emphysema as often as men, but this pattern is changing as women continue to become heavy smokers. Half the people in this country with emphysema are over the age of 65; nearly all the rest are over the age of 45. Frequently, those with emphysema live in areas where air pollution is a problem.


    Early symptoms of chronic obstructive pulmonary disease include mild shortness of breath and a slight "smoker's cough" caused by the narrowing and clogging of airways with mucus - a hallmark of chronic bronchitis.

    Emphysema-related signs and symptoms may also include fatigue, recurrent respiratory infections and weight loss. By the time symptoms appear, people with emphysema may have permanently lost as much as 60 percent lung function. Slight loss of lung function is a normal part of aging; people with emphysema or chronic bronchitis tend to lose lung function faster than non-smokers.

    As the disease worsens, oxygen levels in the blood start to fall and carbon dioxide levels rise. The symptoms of emphysema vary considerably and may be confused with those of other conditions, so doctors rely on chest x-rays, CAT scans, and tests of lung function to make a definitive diagnosis. A key procedure is spirometry, which easily and inexpensively measures a person's ability to force air out of the lungs. Other laboratory tests are used to assess oxygen and carbon dioxide levels in the blood.


    Emphysema patients who quit smoking can expect some improvement in their symptoms as the inflammation of the airways subsides. Clearing of the airways, which would help a patient breathe better, may be aided by following these supportive measures:

    • Stop smoking and avoid air pollution.
    • Do exercises that strengthen the diaphragm and abdominal muscles to help in the breathing process.
    • Clear the lungs of excess mucus by lying in special positions that help drainage.
    • Build strength with a walking and exercise program.
    • Use appropriate combinations of medicines, breathing aids and living patterns to make life more comfortable.
    • Avoid irritating inhalants such as dust, fumes and polluted air. Get a yearly influenza immunization.
    • Avoid respiratory infections. This may mean frequent hand-washing and avoiding crowded spaces during times when colds and the flu are common.
    • Avoid extremes of temperature and stay indoors when air pollution warnings are in effect.
    • Maintain proper nutrition.
    • Adhere to the instructions the doctor has given on the use of medications.

    Bronchodilator medications are usually taken as inhalers to open the airways. In severe cases, such as when the lungs no longer supply adequate oxygen to the body, the doctor may prescribe supplemental oxygen. For cases involving enzyme deficiency, alpha-1-antitrypsin (a new protein intravenous replacement therapy) may be used.

    Breathing patterns that improve symptoms are often discovered by the patient. Pursing the lips during exhalation (so as to keep the small airways from collapsing) and taking longer to exhale than to inhale may be useful.

    An essential aspect of treatment is exercise conditioning. Many patients who follow a regular, sustained exercise program will usually improve their exercise capability. This improvement helps them perform daily and other activities with less shortness of breath.

    Patients can use a stationary exercise bicycle, walk or ride a bicycle outdoors. Exercise can be increased gradually, both in distance and speed. This type of exercise program should be undertaken only after a doctor has evaluated the heart and lung function to determine the safe limits. Certain exercises with light weights can help to strengthen some of the respiratory muscles.

    In some cases, surgery may be helpful. Lung volume reduction surgery, in which the areas of lung most affected by emphysema are removed to help the healthy parts of the lung to function normally, may be helpful in some patients. Patients may also be able to receive a lung transplant.

    Emphysema cannot be cured, but contributing factors can be eliminated and its rate of progression can be slowed if it is detected early and smoking is stopped. With proper therapy, many patients can maintain part-time or full-time employment. The person suffering from emphysema must come to terms with the disease, but he or she may not have to give up as much of work, family, relationships or other pleasures of a full life, as is often feared.


    Do any tests need to be done to rule out other diseases or to determine extent of involvement?

    Is there an enzyme deficiency?

    What type of treatment do you recommend?

    Will you be prescribing any medication? What are the side effects?

    What smoking cessation resource or counseling can you recommend?

    What exercise program do you recommend?

    Will supplemental oxygen therapy be necessary or needed in the future?

    What can be expected in the future from emphysema?

    Are there any signs or symptoms that need to be reported immediately?

    The best bet for fighting emphysema is not smoking.