Emphysema is a factor in the progression of chronic obstructive pulmonary disease (COPD), a condition that limits the flow of air when you breathe out. Emphysema occurs when the air sacs at the ends of your smallest air passages (bronchioles) are gradually destroyed. Smoking is the leading cause of emphysema. As it worsens, emphysema turns the spherical air sacs — clustered like bunches of grapes — into large, irregular pockets with gaping holes in their inner walls. This reduces the number of air sacs and keeps some of the oxygen entering your lungs from reaching your bloodstream. In addition, the elastic fibers that hold open the small airways leading to the air sacs are slowly destroyed, so that they collapse when you breathe out, not letting the air in your lungs escape. Airway obstruction, another feature of COPD, contributes to emphysema. The combination of emphysema and obstructed airways makes breathing increasingly difficult. Treatment often slows, but doesn't reverse, the process.

Complications of Emphysema

Emphysema can increase the severity of other chronic conditions, such as diabetes and heart failure. If you have emphysema, air pollution or a respiratory infection can lead to an acute COPD exacerbation, with extreme shortness of breath and dangerously low oxygen levels. You may need admission to an intensive care unit and temporary support from an artificial breathing machine (ventilator) until the infection clears.

Causes of Emphysema

The causes of emphysema include:

• Smoking. Cigarette smoke is by far the most common cause of emphysema. There are more than 4,000 chemicals in tobacco smoke, including secondhand smoke. These chemical irritants slowly destroy the small peripheral airways, the elastic air sacs and their supporting elastic fibers.
• Protein deficiency. Approximately 1 to 2 percent of people with emphysema have an inherited deficiency of a protein called AAt, which protects the elastic structures in the lungs. Without this protein, enzymes can cause progressive lung damage, eventually resulting in emphysema. If you're a smoker with a lack of AAt, emphysema can begin in your 30s and 40s. The progression and severity of the disease are greatly accelerated by smoking.

Signs & Symptoms of Emphysema

Emphysema symptoms are mild to begin with but steadily get worse as the disease progresses. The main emphysema symptoms are:

• Shortness of breath
• Wheezing
• Chest tightness
• Reduced capacity for physical activity
• Chronic coughing, which could also indicate chronic bronchitis
• Loss of appetite and weight
• Fatigue

Diagnosis of Emphysema

To determine if you have emphysema, your doctor is likely to recommend certain tests, including:

• Spirometry and other 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 how well your lungs deliver oxygen to your bloodstream. During a spirometry, 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 these tests, even if you don't have symptoms of emphysema or COPD.
• Arterial blood gases analysis. These blood tests measure how well your lungs transfer oxygen into, and remove carbon dioxide from, your bloodstream.
• 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.
• Chest X-ray. A chest X-ray can help confirm a diagnosis of emphysema and rule out other causes of shortness of breath, but an X-ray alone isn't enough to make an accurate diagnosis.
• Sputum examination. Analysis of cells in what you cough up (sputum) can help determine the cause of some lung problems.
• Computerized tomography (CT) scan. A CT scan can allow your doctor to view your internal organs, where they'll look for the characteristic "holes" or bullae that are caused by emphysema.

Treatments of Emphysema

The most important step in any treatment plan for smokers with emphysema is to stop 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 smoking cessation 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)

Other emphysema treatments focus on helping you feel better, stay more active and slow the progression of emphysema. They include:

• Bronchodilators. These drugs can help relieve coughing, shortness of breath and trouble breathing by relaxing constricted airways, but they're not as effective in treating emphysema as they are in treating asthma or chronic bronchitis.
• 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.
• GERD treatment. Symptomatic gastroesophageal reflux disease (GERD) aggravates airway disease in many people, so your doctor may recommend medications as well as life style changes to treat it.
• Supplemental oxygen. If you have severe emphysema with low blood oxygen levels, using oxygen regularly at home and when you exercise may provide some relief. Many people use oxygen 24 hours a day. Various forms of oxygen are available, as are different devices to deliver supplemental oxygen to your lungs.
• Pulmonary rehabilitation program. A key part of treatment involves a pulmonary rehabilitation program, which combines education, exercise training and behavioral intervention to help you stay active and improve your health and quality of life. You'll receive help with smoking cessation and your nutritional needs, and you may learn special breathing techniques and ways to conserve energy. Because exercise can help to slow the decline of your lung function, you'll also be given an exercise program.
• Antibiotics. If you develop a bacterial infection like bronchitis or pneumonia, antibiotics are appropriate.
• Inoculations against influenza and pneumonia. If you have emphysema or other forms of COPD, experts recommend influenza (flu) shot annually and pneumonia shot every five years.
• Surgery. In an experimental procedure called lung volume reduction surgery (LVRS), surgeons remove small wedges of damaged lung tissue. Removing the diseased tissue helps the lungs work more efficiently and helps improve breathing. In another surgery, called a bullectomy, doctors remove one or more of the large air spaces (called bullae) that form when the small air sacs are destroyed. This procedure can improve breathing.
• Transplant. Lung transplantation is an option if you have severe emphysema and other options have failed.

Prevention of Emphysema

Most cases of emphysema are preventable. To prevent emphysema:

• Don't smoke. If you do smoke, seek help to quit as soon as possible.
• Avoid exposure to secondhand smoke.
• Wear a mask to protect your lungs if you work with chemical fumes or dust.
• Increase your physical activity or exercise regularly if you've smoked in the past.

When to seek Medical Advice

• You tire quickly, or you can't easily do the things you used to do
• You can't breathe well enough to tolerate even moderate exercise
• Your breathing difficulty worsens when you have a cold
• Your lips or fingernails are blue or gray, indicating low oxygen in your blood
• You frequently cough up yellow or greenish sputum
• You note that bending over to tie your shoes makes you short of breath
• You are losing weight

These signs and symptoms don't necessarily mean you have emphysema, but they do indicate that your lungs aren't working properly and should be evaluated by your doctor as soon as possible.