Emphysema is a progressive lung disease that results in shortness of breath and reduces your capacity for physical activity.
The cause of emphysema is damage to the small air sacs and small airways in your lungs. This damage obstructs airflow when you exhale.
When emphysema is advanced, you must work so hard to expel air from your lungs that just the simple act of breathing can consume a great deal of energy. Unfortunately, because emphysema develops gradually over many years, you may not experience symptoms such as shortness of breath until irreversible damage has already occurred.

When you inhale, air travels to your lungs through two major airways off the windpipe (trachea) called bronchi. Inside your lungs, the bronchi subdivide like the roots of a tree into a million smaller airways (bronchioles) that finally end in clusters of tiny air sacs (alveoli). You have about 300 million air sacs in each lung.
Within the walls of the air sacs are tiny blood vessels (capillaries) where oxygen is added to your blood and carbon dioxide — a waste product of metabolism — is removed. The air sac walls also contain elastic fibers that help the very small airways leading to the air sacs expand like small balloons when you breathe.
In emphysema, inflammation destroys these fragile walls of the air sacs, causing them to lose their elasticity. As a result, the bronchioles collapse, and air becomes trapped in the air sacs, which overstretches them and interferes with your ability to exhale (hyperinflation).
In time, this overstretching may cause several air sacs to rupture, forming one larger air space instead of many small ones. Because the larger, less elastic sacs aren’t able to force air completely out of your lungs when you exhale, you have to breathe harder to take in enough oxygen and to eliminate carbon dioxide.
The process works something like this: Normally, you exhale in two ways, actively and passively. When you sit quietly, your diaphragm contracts and your chest muscles expand to take air in, but your muscles don’t actively contract to let the air out. Instead, the elastic tissue around your air sacs contracts and your lungs passively shrink. On the other hand, when you exert yourself and need more oxygen, your chest muscles contract, forcing air out rapidly.
But if you have emphysema, many of these elastic fibers have been destroyed, and you must consciously force air out of your lungs. The forced exhalation compresses many of your small airways, making expelling air even more difficult.
Cigarette smoke is by far the most common cause of emphysema. The damage begins when tobacco smoke temporarily paralyzes the microscopic hairs (cilia) that line your bronchial tubes. Normally, these hairs sweep irritants and germs out of your airways. But when smoke interferes with this sweeping movement, irritants remain in your bronchial tubes and infiltrate the alveoli, inflaming the tissue and eventually breaking down elastic fibers.
In a small percentage of people, emphysema results from low levels of a protein called alpha-1-antitrypsin (AAt), which protects the elastic structures in your lungs from the destructive effects of certain enzymes. A lack of AAt can lead to progressive lung damage that eventually results in emphysema. If you’re a smoker with a lack of AAt, emphysema can begin in your 30s and 40s.
AAt deficiency is a hereditary condition that occurs when you inherit two defective genes, one from each parent. Although severe AAt deficiency is rare, millions of people carry a single defective AAt gene. Some of these people have mild to moderate symptoms; others have no symptoms at all. Carriers are at increased risk of lung and liver problems and can pass the defect to their children.
People with two defective genes have a high likelihood of developing emphysema, usually between the ages of 30 and 40. The progression and severity of the disease are greatly exacerbated by smoking.
Experts recommend that people with early-onset emphysema — especially those who don’t smoke or who have other risk factors for the disease or who have a family history of AAt deficiency — be tested for the defective gene. People who are found to have a genetic predisposition for AAt deficiency may want to consider having close family members tested as well.

The main emphysema symptoms are shortness of breath and a reduced capacity for physical activity, both of which worsen as the disease progresses. In time, you may have trouble breathing even when lying down, and it may be especially hard to breathe during and after respiratory infections, such as colds or the flu.
Other signs and symptoms of emphysema include:
Chronic, mild cough. Cough is uncommon with emphysema. When it does occur, it’s usually nonproductive, which means that you won’t bring up much phlegm when you cough. If you have a chronic productive cough, you may have chronic bronchitis — another form of chronic obstructive pulmonary disease (COPD) — rather than emphysema.
Loss of appetite and weight loss. It’s a vicious cycle. Emphysema can make eating more difficult, and the act of eating can rob you of your breath. The result is that you simply may not feel like eating much of the time. Also, when you eat, your stomach expands and pushes up the diaphragm, which compresses the lungs and makes it harder to breathe.
Fatigue. You’re likely to feel tired both because it’s more difficult to breathe and because your body is getting less oxygen. You also become out of shape because exercise makes you short of breath.

To determine if you have emphysema, recommend certain tests:

Pulmonary function tests (PFTs). These noninvasive tests can detect emphysema before you have symptoms. They measure how much air your lungs can hold and the flow of air in and out of your lungs. They can also measure the amount of gases exchanged across the membrane between your alveolar wall and capillary membrane. During the test, you’re usually asked to blow into a simple instrument called a spirometer. PFTs may be done before and after the use of inhaled medications to test your response to them. If you’re a smoker or a former smoker, ask your doctor about taking this test, even if you don’t have symptoms of COPD.
Chest X-ray. You’re likely to have a chest X-ray to help rule out other lung problems rather than to diagnose emphysema — because even in the advanced stages of the disease, chest X-rays are often normal.
Arterial blood gases analysis. These blood tests measure how well your lungs transfer oxygen to your bloodstream and how effectively they remove carbon dioxide.
Pulse oximetry. This test involves the use of a small device that attaches to your fingertip. The oximeter measures the amount of oxygen in your blood differently from the way it’s measured in a blood gas analysis. To help determine whether you need supplemental oxygen, the test may be performed at rest, during exercise and overnight.
Sputum examination. Analysis of cells in sputum can help determine the cause of some lung problems.
Computerized tomography (CT) scan. A CT scan allows your doctor to see your organs in two-dimensional images or “slices.” Split-second computer processing creates these images as a series of very thin X-ray beams are passed through your body. A CT scan can detect emphysema sooner than an ordinary chest X-ray can, but it can’t assess the severity of emphysema as accurately as can a pulmonary function test.

Additionally, researchers are studying whether magnetic resonance imaging (MRI) could detect emphysema even before signs and symptoms appear.

The most important step in any treatment plan for smokers with emphysema is stopping smoking; it’s the only way to stop the damage to your lungs from becoming worse. But quitting is never easy, and people often need the help of a comprehensive smokingcessation plan, which may include:

  • A target date to quit
  • Relapse prevention
  • Advice for healthy lifestyle changes
  • Social support systems
  • Medications, such as nicotine gum or patches and the prescription medications bupropion hydrochloride (Zyban) and varenicline (Chantix)

Nicotine replacement products and prescription medications may help curb the irritability, depression and sleep problems that can occur during the first few weeks after quitting smoking.

Other emphysema treatments, which focus on relieving symptoms and preventing complications, include:
Bronchodilators. These drugs can help relieve coughing, shortness of breath and trouble breathing by opening constricted airways, but they’re not as effective in treating emphysema as they are in treating asthma.
Inhaled steroids. Corticosteroid drugs inhaled as aerosol sprays may relieve symptoms of emphysema associated with asthma and bronchitis. Although inhaled steroids have fewer side effects than oral steroids do, prolonged use can weaken your bones and increase your risk of high blood pressure, cataracts and diabetes.
Supplemental oxygen. If you have severe emphysema with low blood oxygen levels, using oxygen at home may provide some relief. Various forms of oxygen are available as well as different devices to deliver them to your lungs. Talk with your doctor about which is best for you and about oxygen distributors in your area. Your dealer can set up your equipment, instruct you on care and maintenance, and provide follow-up visits.
Protein therapy. Infusions of AAt may help slow lung damage in people with an inherited deficiency of the protein.
Antibiotics. Respiratory infections such as acute bronchitis, pneumonia and influenza are a leading complication of emphysema; infections increase the amount of sputum you produce and make breathing problems worse. Broad-spectrum antibiotics may help relieve these symptoms, but should be used with caution to avoid the serious and growing problem of antibiotic-resistant bacteria.
Inoculations against influenza and pneumonia. If you have emphysema or other forms of COPD, experts recommend an influenza (flu) shot annually and a pneumonia shot every five years after age 65.

Surgery. In a procedure called lung volume reduction surgery (LVRS), surgeons remove small wedges of damaged lung tissue. Although it seems counterintuitive to treat diminished lung capacity by further reducing the size of the lungs, the extra space that’s created in the chest cavity appears to help the remaining lung tissue and diaphragm work more efficiently.

A large clinical trial called the National Emphysema Treatment Trial showed that LVRS could improve the lung function of certain people with severe emphysema. Those who benefited had emphysema in the upper lobes of their lungs and a low exercise capacity even after undergoing several weeks of pulmonary rehabilitation.
Improvement in lung function was greatest the first six months after the procedure. After that, lung function gradually declined. By the two-year mark, the lung function in many people was about the same as it was before surgery. If you have severe emphysema and think you may be a candidate for LVRS, discuss the risks and benefits of the operation with your doctor.

Transplant. Lung transplantation is an option if you have severe emphysema and other options have failed.

Pulmonary rehabilitation program. A key part of treatment involves a pulmonary rehabilitation program, which combines education, exercise training and behavioral intervention to help restore you to the highest possible level of independent living.

You’ll receive help with smoking cessation and your nutritional needs, and you may learn special breathing techniques and ways to conserve energy. You’ll also be given an exercise program that’s appropriate for you. This may include aerobic exercises, such as walking and riding an exercise bike, as well as special exercises for your arms and legs.

Some simple exercises can improve your breathing if you have emphysema or another chronic lung disorder. They help you control the emptying of your lungs by using your abdominal muscles. Do them two to four times daily.

Diaphragmatic breathing
To perform this type of breathing exercise, take these steps:

  • Lie on your back with your head and knees supported by pillows. Begin by breathing in and out slowly and smoothly in a rhythmic pattern. Relax.
  • Place your fingertips on your abdomen, just below the base of your rib cage. As you inhale slowly, you should feel your diaphragm lifting your hand.
  • Practice pushing your abdomen against your hand as your chest becomes filled with air. Make sure your chest remains motionless. Try this while inhaling through your mouth and counting slowly to three. Then purse your lips and exhale through your mouth while counting slowly to six.

Practice diaphragmatic breathing on your back until you can take 10 to 15 consecutive breaths in one session without tiring. Then practice it while lying on one side and then on the other. Progress to doing the exercise while sitting erect in a chair, standing up, walking and, finally, climbing stairs.

Pursed-lip breathing
Try the diaphragmatic breathing exercises with your lips pursed as you exhale, that is, with your lips puckered — the flow of air should make a soft “sssss” sound. Inhale deeply through your nose or your mouth, whichever is more comfortable for you, and then exhale. Repeat 10 times at each session. Breathing out against pursed lips increases the air pressure inside the airways, including your very small airways, which minimizes how much they collapse.

Deep-breathing exercise
While sitting or standing, pull your elbows firmly backward as you inhale deeply. Hold the breath in, with your chest arched, for a count to five, and then force the air out by contracting your abdominal muscles and letting your elbows to return to their starting position. Repeat the exercise 10 times.

Other steps you can take
If you have emphysema, you can take a number of steps to halt its progression and to protect yourself from complications:

Stop smoking. This is the most important measure you can take for your overall health and the only one that can halt the progression of emphysema. Join a smoking cessation program if you need help giving up smoking. As much as possible, avoid secondhand smoke. Sit in nonsmoking areas when you’re out, and ask family and friends not to smoke in your home.
Avoid other respiratory irritants. These include fumes from paint and automobile exhaust, some cooking odors, certain perfumes, even burning candles and incense. Change furnace and air conditioner filters regularly to limit pollutants.
Exercise regularly. Try not to let your breathing problems keep you from getting regular exercise, which can significantly increase your capacity for physical activity.
Clear your airways. With emphysema, mucus tends to collect in your air passages and can be difficult to clear. To keep secretions thin and easy to bring up, drink plenty of nonalcoholic fluids every day.
Protect yourself from cold air. During cold weather wear a soft scarf or a cold-air mask — available from a pharmacy — over your mouth and nose to warm the air that’s entering your lungs. You need to put the face mask on before you go out into the cold. For the same reason, breathe through your nose because cold air can cause spasms of the bronchial passages.
Avoid respiratory infections. Get a pneumonia vaccination as advised by your doctor and an annual influenza immunization. Do your best to avoid direct contact with people who have a cold or the flu. If you have to mingle with large groups of people during cold and flu season, wash your hands frequently and carry a small bottle of hand sanitizer in your pocket or purse. Try to avoid touching the inside of your nose or rubbing your eyes, which is the way you acquire most viral infections. If you must be in crowds during colds and flu season, wear a face mask.

Maintain good nutrition. A balanced diet gives your body the nutrients it needs for energy, for building and maintaining cells, and for regulating body processes. Work toward and maintain a desirable body weight. Being overweight requires more oxygen and can interfere with breathing. If you’re underweight, achieving a healthy weight may increase your strength.

When the effort to eat is taxing, you may need to eat smaller meals more frequently. Some people are helped by eating their larger meal earlier in the day and avoiding lying down after meals. Choosing soft, easy-to-digest foods, such as yogurt, rice, baked potatoes, and poached chicken or fish, also may help.