What is emphysema?
Emphysema is a disease of the lungs that usually develops after many years of smoking. Along with asthma and chronic bronchitis, emphysema belongs to a group of lung diseases known as chronic obstructive pulmonary disease (COPD). Once it has developed, emphysema does not reverse, and in fact, only continues to become worse.
Emphysema affects the lungs by destroying their alveoli. Alveoli are small, thin-walled, very fragile air sacs located in clusters at the end of the bronchial tubes deep inside the lungs. As you breathe in air, the alveoli stretch, drawing oxygen in and transporting it to the blood. When you exhale, the alveoli shrink, forcing carbon dioxide out of the body.
When emphysema develops, the alveoli lose their elasticity and there is destruction of lung tissue thus the ability to perform these essential actions. As a result, air becomes trapped in the lungs, over-extending them and occasionally causing some alveoli to actually burst. This trapped air also means less and less oxygen reaches the blood. The over inflation also puts constant pressure on the lungs, forcing them to stretch beyond their normal limits, giving some patients with emphysema a barrel-chested look in appearance.
Who gets emphysema?
It currently affects nearly 2 million people in the United States. It is most common in men between the ages of 50 and 70.
What causes emphysema?
Between 80% and 90% of all cases of emphysema are caused by smoking, thus making it one of the most preventable types of respiratory diseases. Cigarette smoking causes emphysema by irritating the airways. This creates inflammation that narrows the airways, making it more difficult to breathe. Cigarette smoke also causes the cilia to stop working properly, so mucus and particles are not cleaned from the airways.
A small percentage of cases are believed to be caused by prolonged exposure to air polluted with fumes and/or dust, while another small percentage of cases is inherited. These inherited cases are the result of a protein deficiency known as alpha 1-antitrypsin deficiency (A-1ATD).
Alpha 1-antitrypsin is a protein produced in the liver and released into the bloodstream. It allows the lungs to function properly by protecting them from an enzyme released by the white blood cells known as neutrophil elastase. Neutrophil elastase is released by the white blood cells during times of inflammation and is ordinarily helpful in destroying invading bacteria.
For people with A-1ATD, the lack of, or deficiency in this protein, allows the enzyme, which is ordinarily kept in check, to attack the lungs, literally turning the body on itself. A person with A-1ATD who smokes creates and even riskier situation because tobacco and its irritants not only damage the alveoli, but also prompt the body to produce more white blood cells and thus more neutrophil elastase.
What are symptoms of emphysema?
Symptoms of emphysema ordinarily do not display themselves until as much as 50% to 70% of the lung tissue has been destroyed. In part, this is due to symptoms of emphysema being mistaken for another illness. People who develop emphysema are more vulnerable to pneumonia, bronchitis, and other lung infections. Therefore, you should arrange an appointment with your doctor if any of these symptoms arise:
- Shortness of breath, especially during light exercise or climbing steps
- Persistent feeling of not being able to get enough air
- Persistent cough or "smoker’s cough"
- Chronic mucus production
- Distended, barrel-shaped chest
How is emphysema diagnosed?
Of course, diagnosis of emphysema cannot be based solely on symptoms alone. If your doctor thinks that you may have emphysema, there are a number of tests he or she can order. One test may simply involve tapping on your chest and listening with a stethoscope. If the doctor hears a hollow sound, it often indicates that the air sacs have become enlarged or ruptured. Other tests include:
X-rays: X-rays are generally not useful in detecting early stages of emphysema. However, X-rays can aid in diagnosis in moderate or severe cases. Either a plain chest x-ray or a CAT (computer-aided tomography) scan can be used. Once the test is completed, the readings will be compared to results from healthy sets of lungs from people of similar age and background.
Pulse oximetry: Also known as an oxygen saturation test, pulse oximetry is used to measure the oxygen saturation of the blood. This is done by attaching the monitor to a person’s toe, finger, or earlobe. People who have poor blood flow may need to perform light exercise on a treadmill or stationary bicycle so the therapist can obtain an accurate reading.
Spirometry and pulmonary functions tests (PFT): One of the most useful tests in determining airway obstruction, a spirometry or PFT tests the lungs’ volume by measuring the maximum airflow while a patient both inhales and exhales. This is done by taking a deep breath and then blowing into a tube hooked up to a specialized machine.
Arterial blood gas: Often used for more advanced cases of emphysema, this test analyzes blood from an artery, measuring it for amounts of oxygen and carbon dioxide. This is especially helpful in determining whether a patient may need supplemental oxygen.
Electrocardiogram (EKG): EKGs may be performed to check heart function and rule out heart disease as a cause of shortness of breath.
How is emphysema treated?
Because emphysema worsens with time and there is no known cure, treatment is generally directed toward reducing the rate of progress. The type of treatment will depend on the severity of the disease.
Quitting smoking: If you smoke, quitting is the most important step you can take to protect your lungs. It is never too late to quit. Your doctor can help you find the right smoking cessation method.
Bronchodilator medications: Often used for patients with asthma, these types of medicines relax the muscles around the airways and can benefit emphysema patients who frequently suffer from tight airway constriction. Bronchodilators are often initially tried as an inhalant because inhalants produce more immediate results and have fewer side effects than oral medications
Anti-inflammatory medication: Also known as corticosteroids, these medications may be given for any inflammation that occurs with emphysema in an effort to soothe the thin walls of airways. There are long-term effects to keep in mind when taking anti-inflammatories, however, such as osteoporosis, hypertension, high blood sugar and fat redistribution.
Oxygen therapy: Oxygen therapy is prescribed for patients whose lungs are not getting enough oxygen to the blood (hypoxemia). These patients are unable to absorb enough oxygen from the outside air and require oxygen to be administered by a nasal catheter or a facemask. Patients receiving oxygen therapy require arterial blood gas tests and pulse oximetry measurements to check oxygen levels in the blood.
Lung volume reduction surgery: A relatively new procedure, lung volume reduction surgery involves removing up to 35% of diseased lung tissue, then joining together the remaining tissue. Doing this may relieve pressure on the breathing muscles and help improve lung elasticity. The results of the surgery, both initially and up to 18 months afterwards, have been very promising. However, the surgery does come with a high complication rate, and exactly which patients are the best candidates for this surgery is still being determined.
What are some tips for managing emphysema?
Knowledge is the best tool for managing or preventing emphysema. Knowing the correct precautions or which changes in behavior to make may help you prevent or reduce the risk of further complications. It is important for you to do what you can to prevent respiratory infections by:
- Practicing good handwashing
- Taking care of your mouth and teeth by brushing and using antibacterial mouth rinse after each meal. Floss daily.
- Keeping breathing equipment clean
- Keeping your house clean and free of dust
- Getting a flu shot every year
- Following a doctor-prescribed exercise program
- Avoiding irritants such as:
- Cigarette smoke
- Exhaust fumes
- Strong perfumes
- Cleaning products
- Pet dander
Where can I learn more about emphysema?
American Lung Association
1301 Pennsylvania Avenue NW, Suite 800
Washington, DC 20004
The National Emphysema Foundation
128 East Avenue
Norwalk, CT 06851
American College of Chest Physicians. Living Well with COPD: Chronic Bronchitis and Emphysema. Patient Education Guide www.chestnet.org/ Accessed 9/30/2011
National Heart Lung and Blood Institute. Health Topics: What is COPD? www.nhlbi.nih.gov/ Accessed 9/30/2011
Centers for Disease Control and Prevention. FASTSTATS: Chronic obstructive pulmonary disease. www.cdc.gov/ Accessed 9/30/2011
© Copyright 1995-2011 The Cleveland Clinic Foundation. All rights reserved.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 9/13/2011…#9370