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Medically reviewed by Last updated on Mar 24, 2023.

What is Emphysema?

Harvard Health Publishing

Emphysema is a respiratory disease. In this condition, millions of the lungs' tiny air sacs (alveoli) stretch out of shape or rupture. As these thin, fragile air sacs become damaged or destroyed, the lungs lose their natural elasticity. They become unable to empty easily.

Emphysema is a progressive disease, which means it continues to get worse. As the condition progresses, the lungs lose their ability to absorb oxygen and release carbon dioxide. Breathing becomes more difficult. A person feels easily short of breath, like he or she is not getting enough air.

Emphysema and chronic bronchitis are the two most common forms of chronic obstructive pulmonary disease (COPD). They often occur together. Bronchitis is an inflammation and swelling of the bronchial walls. A person with chronic bronchitis typically has a daily cough with phlegm that lasts for months at a time over several years.

Smoking is responsible for the vast majority of cases of emphysema. Exposure to secondhand smoke and airborne toxins also can contribute to emphysema, though to a much lesser degree. Smokers exposed to high levels of air pollution appear to be at higher risk of developing COPD.

Both emphysema and chronic bronchitis are caused by damage to the lungs and bronchial tubes. When the damage is caused by smoking, symptoms may improve after a smoker quits.

A small number of people in the United States develop emphysema from an inherited disease known as alpha 1-antitrypsin deficiency. In this genetic condition, the body doesn't make enough of a protein called alpha 1-antitrypsin (AAT). AAT protects the lungs from damage by enzymes. When levels of AAT are low, the lungs are prone to being damaged by these enzymes. Smoking makes this condition worse.


During the early stages of emphysema, most people will have few symptoms. The disease usually progresses slowly. Changes in breathing may be hardly noticed. A typical person will not experience symptoms until they have smoked a pack of cigarettes per day for more than 20 years.

However, over time, almost all people with emphysema will develop shortness of breath. At first, this may be noticed only during strenuous activities, such as climbing several flights of stairs or playing sports. As time goes on, the shortness of breath may occur with daily activities, such as housework or walking short distances. Eventually, the person may be short of breath for much of the day, even while at rest or sleeping. At its worst, emphysema can cause "air hunger." This is the constant feeling of being unable to catch one's breath.

These respiratory symptoms are the same regardless of the cause of the emphysema. However, two people with the same degree of lung damage may have different symptoms. One person with mild emphysema may feel very short of breath. Another person with more advanced stages of the disease may be hardly bothered by symptoms.

Other symptoms caused by emphysema include:


Your doctor will ask for details about your smoking. He or she will ask how long you've smoked, and how many cigarettes per day.

Other questions may include:

Your doctor also will ask about your respiratory symptoms. He or she will want to know if and when you develop shortness of breath. The doctor also may wish to ask about:

Your doctor then will examine you to look for typical signs of emphysema. This may include:

The results of this examination may be totally normal in many people in the earliest stages of emphysema.

In most people, emphysema will be diagnosed by X-ray or lung-function tests.

A regular chest X-ray may show typical changes of emphysema. These include:

However, these changes may not appear until significant damage has occurred. Computed tomography (CT) scans are better for detecting the earliest changes of emphysema. CT scans may help to diagnose the disease in younger people or those who have never smoked.

Pulmonary function testing is useful both to diagnose emphysema and to determine the stage of the disease. This test is also known as spirometry. In this test you will blow forcefully through a tube. The tube is connected to a machine that measures your lung capacity.

Your doctor also may order specialized lung tests. These may require you to sit inside a glass box, or slowly breathe in a mixture of different gases.

Other tests your doctor may order include:

If suspected, your doctor can order a blood test to confirm the diagnosis of AAT deficiency. If this test is positive, your doctor may recommend screening for your entire family.

Expected duration

Regardless of the cause, lung damage in emphysema cannot be reversed. If the disease is not treated, damage and symptoms will continue to get worse. If treated, the symptoms can improve.


If you smoke, stop. If you don't smoke, don't start. By quitting smoking you can either prevent emphysema or slow its progression.

You also should limit your exposure to air pollution. Restrict your outdoor activity when there are reports of high smog levels.

People exposed to harmful chemicals at work should speak to their employers about respirator masks. Or, consult with a specialist in occupational medicine.

If you have emphysema, ask your doctor about vaccinations against influenza (flu) and pneumococcal pneumonia. These vaccinations can help to prevent life-threatening respiratory infections in people with lung disease.


No treatment can reverse or stop emphysema. But treatment can help to:

Doctors' top treatment advice is to quit smoking. This is the single most important factor for maintaining healthy lungs. Stopping smoking is most effective at the early stages of emphysema. But it also can slow the loss of lung function in later stages of the disease.

People with AAT deficiency may be candidates for replacement therapy. This is done with infusions of natural AAT obtained from donors. This form of treatment appears effective. But it is time consuming and very expensive.

Your doctor may prescribe a number of different medications. These can help to relieve symptoms. Medications may include:

These medications are taken through hand-held inhalers or machine-driven nebulizers. These create a fine mist that can be inhaled.

Bronchodilators help to open the bronchial tubes in your lungs. By doing so, they reduce shortness of breath, wheezing and cough.

Theophylline (sold under several brand names) is a pill form of a bronchodilator. Because it can interact with medications and cause side effects, it is used less often than the inhaler medications.

Inhaled corticosteroids or pills may be prescribed for daily use. They help control the inflammation of chronic bronchitis.

These combination products provide both anti-inflammatory action and airway opening in one inhaler.

Oxygen therapy increases life expectancy in people with emphysema who have below-normal levels of oxygen in the blood. Oxygen usually is given through a plastic tube (nasal cannula) worn under the nostrils. The oxygen may be stored in metal cylinders. Or, it may be purified from air by an oxygen concentrator.

A number of lightweight, portable devices are available. They allow those who need oxygen to leave their homes for hours at a time.

Some people with emphysema need oxygen only at night.

Supplying oxygen at home is very expensive. As a result, most medical insurance companies have strict requirements to qualify for home oxygen.

People with emphysema also are at risk of becoming malnourished. It is important to see your doctor regularly about an appropriate diet. They are also at risk for developing psychological problems such as anxiety or depression. Counseling or medications can help.

Pulmonary rehabilitation is a form of physical therapy. It includes a structured exercise program combined with special breathing techniques, psychological support and education. It helps people with emphysema:

Other treatments may be considered for people with advanced stages of emphysema.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

When to call a professional

Call your doctor if you develop:

If you smoke, see your doctor about ways to quit. Several different types of treatment can increase your likelihood of success compared to "going cold turkey." These include medications and counseling.

You also should see your doctor if anyone in your family has been diagnosed with AAT deficiency.


There is no cure for emphysema. But the condition can be controlled.

People with mild emphysema who quit smoking have a normal life expectancy. Those who adopt good health habits can enjoy a fairly normal lifestyle for a long time. Even people whose emphysema is severe have a good chance of surviving for five years or more.

In people with emphysema who continue to smoke, smoking dramatically increases the severity of the illness. It may reduce life span by 10 years or more.

Additional info

American Lung Association

National Heart, Lung, and Blood Institute (NHLBI)

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.