- What Is Emphysema?
- What Causes Emphysema?
- What Are Emphysema Symptoms and Signs?
- When to Seek Medical Care and Who to See
- How to Test for Emphysema
- What Is Emphysema Medical Treatment?
- What Is Emphysema Surgery?
- Importance of Pulmonary Rehabilitation
- Emphysema Follow-up
- Emphysema Prevention
- Emphysema Prognosis
What Is Emphysema?
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath due to over-inflation of the alveoli (air sacs in the lung). In people with emphysema, the lung tissue involved in exchange of gases (oxygen and carbon dioxide) is impaired or destroyed. Emphysema is included in a group of diseases called chronic obstructive pulmonary disease or COPD (pulmonary refers to the lungs). Emphysema is called an obstructive lung disease because airflow on exhalation is slowed or stopped because over-inflated alveoli do not exchange gases when a person breaths due to little or no movement of gases out of the alveoli.
Emphysema changes the anatomy of the lung in several important ways. This is due to in part to the destruction of lung tissue around smaller airways. This tissue normally holds these small airways, called bronchioles, open, allowing air to leave the lungs on exhalation. When this tissue is damaged, these airways collapse, making it difficult for the lungs to empty and the air (gases) becomes trapped in the alveoli.
Normal lung tissue looks like a new sponge. Emphysematous lung looks like an old used sponge, with large holes and a dramatic loss of “springy-ness” or elasticity. When the lung is stretched during inflation (inhalation), the nature of the stretched tissue wants to relax to its resting state. In emphysema, this elastic function is impaired, resulting in air trapping in the lungs. Emphysema destroys this spongy tissue of the lung and also severely affects the small blood vessels (capillaries of the lung) and airways that run throughout the lung. Thus, not only is airflow affected but so is blood flow. This has dramatic impact on the ability for the lung not only to empty its air sacs called alveoli (pleural for alveolus) but also for blood to flow through the lungs to receive oxygen.
What Causes Emphysema?
Cigarette smoking is by far the most dangerous behavior that causes people to develop emphysema, and it is also the most preventable cause. Other risk factors include a deficiency of an enzyme called alpha-1-antitrypsin, air pollution, airway reactivity, heredity, male sex, and age.
The importance of cigarette smoking as a risk factor for developing emphysema cannot be overemphasized. Cigarette smoke contributes to this disease process in two ways. It destroys lung tissue, which results in the obstruction of air flow, and it causes inflammation and irritation of airways that can add to air flow obstruction.
- Destruction of lung tissue occurs in several ways. First, cigarette smoke directly affects the cells in the airway responsible for clearing mucus and other secretions. Occasional smoking temporarily disrupts the sweeping action of tiny hairs called cilia that line the airways. Continued smoking leads to longer dysfunction of the cilia. Long-term exposure to cigarette smoke causes the cilia to disappear from the cells lining the air passages. Without the constant sweeping motion of the cilia, mucous secretions cannot be cleared from the lower respiratory tract. Furthermore, smoke causes mucous secretion to be increased at the same time that the ability to clear the secretions is decreased. The resulting mucous buildup can provide bacteria and other organisms with a rich source of food and lead to infection.
- The immune cells in the lung, whose job it is to prevent and fight infection, are also affected by cigarette smoke. They cannot fight bacteria as effectively or clear the lungs of the many particles (such as tar) that cigarette smoke contains. In these ways cigarette smoke sets the stage for frequent lung infections. Although these infections may not even be serious enough to require medical care, the inflammation caused by the immune system constantly attacking bacteria or tar leads to the release of destructive enzymes from the immune cells.
- Over time, enzymes released during this persistent inflammation lead to the loss of proteins responsible for keeping the lungs elastic. In addition, the tissue separating the air cells (alveoli) from one another also is destroyed. Over years of chronic exposure to cigarette smoke, the decreased elasticity and destruction of alveoli leads to the slow destruction of lung function.
- Alpha-1-antitrypsin (also known as alpha-1-antiprotease) is a substance that fights a destructive enzyme in the lungs called trypsin (or protease). Trypsin is a digestive enzyme, most often found in the digestive tract, where it is used to help the body digest food. It is also released by immune cells in their attempt to destroy bacteria and other material. People with alpha-1-antitrypsin deficiency cannot fight the destructive effects of trypsin once it is released in the lung. The destruction of tissue by trypsin produces similar effects to those seen with cigarette smoking. The lung tissue is slowly destroyed, thus decreasing the ability of the lungs to perform appropriately. The imbalance that develops between trypsin and antitrypsin results in an “innocent bystander” effect. Foreign objects (e.g. bacteria) are trying to be destroyed but this enzyme destroys normal tissue since the second enzyme (antiprotease) responsible for controlling the first enzyme (protease) is not available or is poorly functioning. This is referred to as the “Dutch” hypothesis of emphysema formation.
- Air pollution acts in a similar manner to cigarette smoke. The pollutants cause inflammation in the airways, leading to lung tissue destruction.
- Close relatives of people with emphysema are more likely to develop the disease themselves. This is probably because the tissue sensitivity or response to smoke and other irritants may be inherited. The role of genetics in the development of emphysema, however, remains unclear.
- Abnormal airway reactivity, such as bronchial asthma, has been shown to be a risk factor for the development of emphysema.
- Men are more likely to develop emphysema than women. The exact reason for this is unknown, but differences between male and female hormones are suspected.
- Older age is a risk factor for emphysema. Lung function normally declines with age. Therefore, it stands to reason that the older the person, the more likely they will have enough lung tissue destruction to produce emphysema.
It is important to emphasize that COPD is often not purely emphysema or bronchitis, but varying combinations of both.
What Are Emphysema Symptoms and Signs?
Shortness of breath is the most common symptom of emphysema. Cough, sometimes caused by the production of mucus, and wheezing may also be symptoms of emphysema. You may notice that your tolerance for exercise decreases over time. Emphysema usually develops slowly. You may not have any acute episodes of shortness of breath. Slow deterioration is the rule, and it may go unnoticed. This is especially the case if you are a smoker or have other medical problems that limit your ability to exercise.
One of the hallmark signs of emphysema is "pursed-lipbreathing." The person with emphysema struggles to exhale completely, in an attempt to empty trapped air. They purse their lips, leaving only a small opening. Then, when they exhale, the lips block the flow of air, increasing pressure in the collapsed airways, and opening them, allowing the trapped air to empty.
People with emphysema may develop a "barrel chest," where the distance from the chest to the back, which is normally less than the distance side to side, becomes more pronounced. This is a direct result of air becoming trapped behind obstructed airways.
When to Seek Medical Care and Who to See
If you have new or worsening shortness of breath, seek medical attention from your doctor and pulmonologist. Shortness of breath can occur with other diseases, particularly heart disease and other lung diseases, so it is important not to overlook or minimize this symptom. A gradual decrease in the ability to exercise or perform daily activities, a persistent cough, and wheezing also suggest a visit to the doctor.
Because cigarette smoking is such a dangerous risk factor for emphysema, you may also wish to contact your doctor for help with making a plan to quit smoking, even in the absence of shortness of breath or other symptoms. Doctors can offer you many options to help you stop smoking. The support from a doctor may make the process easier than doing it alone. Many recent studies have shown that up to 25% of smokers may have COPD and not know it.
Shortness of breath should always be taken seriously, especially if it comes on suddenly or if it gets worse over a relatively short period of time; this situation is usually considered a medical emergency so medical care should be sought immediately.
- If you know you have emphysema, go to the hospital's emergency department with any new, severe, or worsening shortness of breath. The inability to speak in full sentences may be a sign of shortness of breath.
- Any hint of the lips, tongue, fingernails, or skin turning a shade of blue should prompt a visit to the hospital's emergency department. This sign, called cyanosis, can indicate severe worsening of your lung condition.
- The failure of shortness of breath to improve or worsening shortness of breath in spite of home medications can indicate the need for emergency department care.
- A new or worsening cough can be a sign of an infection, such as pneumonia, and should prompt a timely visit to a primary care physician or a hospital's emergency department for evaluation. Increased sputum production may also be a sign of infection. Infections make emphysema worse and can lead to long-term problems.
How to Test for Emphysema
When a doctor suspects you have emphysema, based on your complaints, a physical examination will be performed. The doctor will pay particular attention to your breathing sounds, your heart sounds, and your general physical appearance. A number of tests may be ordered or performed in the office or in the Emergency Department. These tests serve to clarify the extent of the disease, the remaining lung function, and the presence of lung infections.
- A chest X-ray helps the doctor to identify changes in your lung that may indicate emphysema. The X-ray also may show the presence of an infection or a mass in the lung (such as a tumor) that could explain your symptoms. Shortness of breath has many causes. The chest X-ray is considered by most doctors to be the quickest and easiest test to begin to separate the different possible causes and formulate a diagnosis.
- Lung function tests can give the doctor specific information about how the lungs work mechanically. These tests involve having you breathe into a tube that is connected to a computer or some other monitoring device, which can record the necessary information. The tests measure how much air your lungs can hold, how quickly your lungs can expel air during expiration, and how much reserve capacity your lungs have for increased demand, such as during exercise.
- If you have a family history of alpha-1-antitrypsin deficiency, the doctor may wish to send a blood test to evaluate for this genetic disease.
- Blood tests may also be used to check your white blood cell count, which can sometimes indicate an acute infection. This information can be used with the chest X-ray to evaluate for pneumonia, bronchitis, or other respiratory infections that can make emphysema worse.
- Another blood test that may be helpful, especially in the hospital setting, is called the arterial blood gas. This test helps doctors determine how much oxygen and carbon dioxide are in your blood.
What Is Emphysema Medical Treatment?
Treatment for emphysema can take many forms. Different approaches to treatment are available. Generally, a doctor will prescribe these treatments in a step-wise approach, depending on the severity of your condition.
- Stop smoking: Although not strictly a treatment, most doctors make this recommendation for people with emphysema (and everyone). Quitting smoking may halt the progression of the disease and should improve the function of the lungs to some extent. Lung function deteriorates with age. In those susceptible to developing COPD, smoking can result in a five-fold deterioration of lung function. Smoking cessation may return lung function from this rapid deterioration to its normal rate after smoking is stopped. A doctor may be able to prescribe medications to help in breaking the addiction and can also recommend behavioral therapies, such as support groups. You and your doctor should work to find an approach that results in the successful end to cigarette smoking and, in the process, the beginning of improved lung function and quality of life.
- Bronchodilating medications: These medications, which cause the air passages to open more fully and allow better air exchange, are usually the first medications that a doctor will prescribe for emphysema. In very mild cases, bronchodilators may be used only as needed, for episodes of shortness of breath.
- The most common bronchodilator for mild cases of emphysema is albuterol (Proventil or Ventolin). It acts quickly, and 1 dose usually provides relief for 4-6 hours. Albuterol is most commonly available as a metered-dose inhaler or MDI, and this is the form that is used most often for patients with mild emphysema, with intermittent shortness of breath. When used for this purpose, some people refer to their albuterol inhaler as a "rescue" medication. It acts to rescue them from a more serious attack of shortness of breath.
- If you have some degree of shortness of breath at rest, a doctor may prescribe the albuterol to be given at regularly scheduled intervals, either through the MDI, or by nebulization. Nebulization involves breathing in liquid medication that has been vaporized by a continuous flow of air (in much the same way a whole-room vaporizer causes liquid droplets to enter the air by the flow of air through water). Nebulized albuterol may be prescribed once scheduled doses via inhaler are no longer adequate to alleviate shortness of breath.
- Ipratropium bromide (Atrovent) is another bronchodilating medication that is used for relatively mild emphysema. Similar to albuterol, it is available in both an inhaler and as a liquid for nebulization. Unlike albuterol, however, ipratropium bromide is usually given in scheduled intervals. Therefore, it is not usually prescribed for "rescue" purposes. Atrovent lasts longer than albuterol, however, and often provides greater relief. Tiotropium (Spiriva) is a long acting form of ipratropium. This once a day medicine has shown to result in a fewer hospitalizations and possible increased survival in some patients with COPD.
- Methylxanthines (Theophylline) and other bronchodilating medications are available that have varying properties that may make them useful in certain cases. Theophylline (Theo-Dur, Uniphyl) is a medication given orally (tablets). It can have a sustained effect on keeping air passageways open. Theophylline levels must be monitored by blood tests. This medicine is used less frequently today due to its narrow therapeutic window. Too much theophylline can produce an overdose; too little, and there will not be enough relief of shortness of breath. In addition, other drugs can interact with theophylline, altering the blood level without warning. For this reason, doctors now prescribe theophylline after very carefully considering its potential for other drug interactions. If you take theophylline, take the medication as prescribed and check with your doctor before starting any new medication. Some new studies are suggesting that very low dose theophylline may have anti-inflammatory properties as well. Theophylline used to be widely prescribed; currently it is prescribed infrequently and usually only in special circumstances because of its narrow range of effectiveness, necessity of blood level monitoring and its interactions with other drugs.
- Steroid medications: They decrease inflammation in the body. They are used for this effect in the lung and elsewhere and have been shown to be of some benefit in emphysema. However, not all people will respond to steroid therapy. Steroids may either be given orally or inhaled through an MDI or another form of inhaler.
- Antibiotics: These medications are often prescribed for people with emphysema who have increased shortness of breath. Even when the chest x-ray does not show pneumonia or evidence of infection, people treated with antibiotics tend to have shorter episodes of shortness of breath. It is suspected that infection may play a role in an acute bout of emphysema, even before the infection worsens into a pneumonia or acute bronchitis.
- Data now suggests that when patients with COPD have a sudden worsening of their symptoms of cough and shortness of breath (also termed an exacerbation), brief and immediate use of steroids and antibiotics can reduce hospitalizations.
- Oxygen: If you have shortness of breath and go to a hospital's emergency department, you often are given oxygen. It may even be necessary to give oxygen by placing a tube in your windpipe and allowing a machine to assist your breathing (also termed tracheal intubation). In some cases, it may be necessary for you to receive oxygen at home as well. There are home-based oxygen tanks available and portable units that enable you to be mobile and engage in normal day-to-day activities.
What Is Emphysema Surgery?
Surgical options are available to some people with advanced emphysema.
- Lung Volume Reduction surgery (LVRS): Although it may not make sense that reducing the size of the lung could help the shortness of breath from emphysema, it is important to remember that emphysema causes an abnormal expansion of the chest wall, which decreases the efficiency of breathing. This surgery is only effective if both upper lobes of the lungs are involved. Removal of this involved lung allows for better expansion of the lower portion of lungs. In a select group of emphysema patients this can improve quality of life for a period of years. Newer studies are underway using one way valves placed in the airways to simulate this volume reduction. The effectiveness of this less invasive procedure is undergoing study at this time.
- Lung transplant: For people with the most advanced disease, transplantation of either one or both lungs can produce a near-cure. Transplantation brings with it another set of risks and benefits. People who undergo transplantation, however, will have to take medication to prevent the rejection of the transplant by the body. Also, not everyone qualifies for transplantation, and those who do are limited by the short supply of available organs.
Importance of Pulmonary Rehabilitation
Pulmonary rehabilitation is probably the most effective therapy for COPD patients with emphysema. Graded physical exercise, proper breathing techniques, education about the disease and available therapies empowers the patient. It improves quality of life and decreases hospitalizations.
If you have emphysema, follow-up care is crucial to managing this disease. You need to become a partner with your doctor in the management of your health.
As Benjamin Franklin wrote, "An ounce of prevention is worth a pound of cure." Realistically, the "cures" or treatments available to doctors and people dealing with emphysema are far more difficult and far less effective than preventing the progression of the disease in the first place.
The prevention of emphysema is closely linked to the prevention of smoking. The primary risk factor for this disease that you can control is the smoking of cigarettes. Those who are daily smokers put themselves and their health at increasing risk with every pack of cigarettes and with every year they continue to smoke. For individuals that have emphysema caused by other causes such as air pollution, avoiding the pollution is the best first step toward prevention.
Flare-ups of emphysema can be reduced or prevented by taking medications as prescribed and seeking medical care for any signs or symptoms of respiratory infection or shortness of breath. Also, if you have emphysema, you should keep current on vaccines that can prevent respiratory infection. It is important to obtain the pneumococcal vaccine every 5 years and the influenza virus vaccine every year, before flu season.
Emphysema is a chronic lower respiratory disease, the third leading cause of death in the United States. It is a chronic, progressive disease that affects the quality of life at least as much as the length of life.
Similar to many chronic diseases, the prognosis is affected by too many variables to be discussed here. There is no cure, but there are effective methods of treatment, which can slow the progression of the disease and allow for a normal life.
In short, the diagnosis of emphysema is not a death sentence. Rather, it is a medical condition that should prompt you to take an active role in the management of your disease. Quitting smoking is the best first step. Regular visits to your doctor and taking medications as prescribed are also very important. However, the prognosis decreases if the individual decides to continue to smoke.
Medically reviewed by James E Gerace, MD; American Board of Internal Medicine with subspecialty in Pulmonary Disease
eMedicine.com. Chronic Obstructive Pulmonary Disease and Emphysema
Previous contributing authors and editors: Author: Christopher J Ware, MD, Staff Physician, Department of Emergency Medicine, Temple University School of Medicine.
Coauthor(s): Joseph S Bushra, MD, FAAEM, Adjunct Assistant Professor of Emergency Medicine, Temple University School of Medicine Philadelphia, PA, Attending Physician, Department of Emergency Medicine, The Lankenau Hospital Wynnewood, PA.
Editors: Ruben Olmedo, MD, Chief, Division of Toxicology, Clinical Assistant Professor, Department of Emergency Medicine, Mount Sinai Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; James S Cohen, MD, Consulting Staff, James Cohen, PC.