Emphysema and another lung condition known as chronic bronchitis (persistent cough with phlegm) are both features of a common lung disease called chronic obstructive pulmonary disease (COPD).
Emphysema is generally caused by cigarette smoking or long-term exposure to certain industrial pollutants or dusts. A small percentage of cases are caused by a familial or genetic disorder, alpha-1-antitrypsin deficiency.
While damaged airways don’t regenerate and there is no cure, emphysema is preventable and treatable.
Symptoms of emphysema
The symptoms of emphysema include:
- breathlessness with exertion, and eventually breathlessness all the time in advanced disease
- susceptibility to chest infections
- cough and phlegm production
- barrel-shaped chest (from expansion of the ribcage in order to accommodate enlarged lungs)
- cyanosis (a blue tinge to the skin) due to lack of oxygen.
Structure of the lungs
The lungs are sponge-like structures that lie within the chest, protected by the ribcage.
They are made up of progressively branching air passages, the smallest of which end in minute air sacs, where inhaled oxygen is transferred to the blood stream and carbon dioxide (produced in many of the body’s chemical reactions) is transferred from the blood into the exhaled breath.
Inhaled air is directed down the trachea (windpipe), which divides into two passages called bronchi and they distribute the inhaled air, one to each lung.
The bronchi divide into smaller tubes called bronchioles, and further still into tiny air sacs called alveoli. Each alveolus is encased by a fine mesh of capillaries, through which the exchange of oxygen and carbon dioxide takes place.
Oxygen molecules dissolve and move across a thin film of moisture from the air sac to the bloodstream. Blood carrying oxygen travels to the heart and is then pumped around the body.
At the same time, carbon dioxide in the blood crosses from the capillaries to the air sacs, using the same film of moisture. The carbon dioxide leaves the body within the exhaled breath.
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.
Complications of emphysema
Complications of emphysema can include:
- Pneumonia – this is an infection of the alveoli and bronchioles. A person with emphysema is more prone to pneumonia.
- Collapsed lung – some lungs develop large air pockets (bullae), which may burst, resulting in lung deflation (also called pneumothorax).
- Heart problems – damaged alveoli, reduced number of capillaries and lower oxygen levels in the blood stream may mean that the heart has to pump strongly to move blood through the lungs. Over time, this can place considerable strain on the heart.
Diagnosis of emphysema
COPD, including emphysema, is diagnosed mainly using a lung function test called spirometry. Other tests may help in diagnosis of emphysema including:
- other lung function (or breathing) tests
- chest x-rays
- CT scans
When to Seek Medical Care
If you have new or worsening shortness of breath, seek medical attention from your doctor. 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.
Treatment for emphysema
There is no cure for emphysema, although it is treatable. Appropriate management has been shown to reduce symptoms, improve quality of life and help people stay out of hospital.
- smoking cessation (immediate and complete smoking cessation is the most effective treatment for COPD and emphysema) and avoidance of other air pollutants
- respiratory (pulmonary) rehabilitation programs
- oxygen treatment, in advanced cases
- anti-inflammatory medications, medicine to widen the airways (bronchodilators) and loosen the phlegm, and antibiotics
- stress management techniques
- gentle, regular exercise to improve overall fitness
- influenza vaccination (yearly) and pneumococcal vaccination to protect against certain types of respiratory infection.
Respiratory rehabilitation programs
A person with emphysema can take part in a respiratory rehabilitation program, commonly known as ‘pulmonary rehab’. These programs:provide information and education on emphysema
- introduce people to an exercise program proven to improve emphysema symptoms
- improve lung function through specific breathing exercises
- teach stress management techniques
- offer advice on adapting to life with emphysema
- provide emotional support through shared experiences.
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.