|The Lungs and the Respiratory System
The respiratory system, including the lungs, brings air into the body. The oxygen in the air travels from the lungs through the bloodstream to the cells in parts of the body. The cells use the oxygen as fuel and give off carbon dioxide as a waste gas. This waste gas is carried by the bloodstream back the lungs to be eliminated or exhaled. The lungs accomplish this vital process, called gas exchange, using an automatic and quickly adjusting system.
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The Lungs at Work
In addition to gas exchange, the lungs and the other parts of the respiratory system have important jobs to do related to breathing. These include:
Bringing all air to the proper body temperature
Moisturizing the inhaled air for necessary humidity
Protecting the body from harmful substances by coughing, sneezing, filtering or swallowing them, or by alerting the body through the sense of smell.
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Defending the lungs with:
1. cilia - microscopic hairs along the air passages
2. mucus (sputum or phlegm - a moving carpet of mucus collects dirt and germs inhaled into the lungs and moves them out to be coughed up or swallowed
3. macrophages - scavenger cells in the lungs that literally eat up dirt and germs invading the lungs.
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What Are the Warning Signs of Lung Disease?
The most frequent warning signs of lung disease are listed below. If you are experiencing any of these symptoms, discuss them with
a doctor as soon as possible.
- "Chronic Cough - Any cough that has lasted a month is chronic. This is an important early symptom indicating something is wrong with your breathing system, regardless of your age.
- "Shortness of Breath - Shortness of breath that continues after a brief rest following normal exercise, or comes after little or no exertion, is not normal. Labored or difficult breathing, the feeling that it is hard to draw air into your lungs or breathe it out, is also a warning sign.
- "Chronic Mucus Production - Mucus, or sputum, is produced by the lungs as a defense response to infection or irritants. If your mucus production has lasted a month, this could indicate lung disease.
- "Wheezing - Noisy breathing or wheezing is a sign that something unusual is blocking the airways of your lungs or making the airways too narrow.
- "Coughing up Blood (Hemoptysis) - If you are coughing up blood, the blood may be coming from your lungs or upper respiratory tract. Whatever the source of the blood, it is a sign of a health problem.
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What Do the Symptoms Mean?
Experts agree that your lungs are not healthy if you have any of these symptoms. You must have them checked out by a doctor. If you wait for symptoms to become severe, you have already lost valuable treatment time. Taking care of mild Symptoms can actually be to your advantage.
Even if you have only one of the symptoms of lung disease - chronic cough, shortness of breath or difficult breathing, mucus, wheezing, or frequent chest colds - you should see a doctor. Most lung disease can be helped by treatment and can even be reversed if caught early.
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How Will Your Doctor Diagnose Your Symptoms?
A doctor will usually use simple tests to determine if you have a lung disease. He or she will take a medical history and give you a complete physical examination. Your examination may include some laboratory tests like a chest X ray, blood tests, a mucus (sputum) examination, and a pulmonary function test, which is a painless procedure that shows the doctor how well your lungs work when you breathe. Exercise testing may also be done to examine the body's response to exertion or physical activity.
Health experts advise a tuberculosis (TB) skin test for various groups of people, including all persons who are HIV-positive, meaning that they have tested positive for the Human Immunodeficiency Virus that causes AIDS. Since the TB test reaction may be misleading in AIDS, a chest X ray and complete physical exam may be recommended even if the tuberculin test is negative. (See #3 below under "Common Lung Hazards.")
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Common Lung Hazards
Any substance that is breathed in affects what happens to the lungs. Many of these substances can be hazardous and threaten the lungs' ability to work properly. Such hazards may include:
- 1. Cigarette Smoking - The major cause of chronic obstructive pulmonary disease (COPD) and lung cancer is cigarette smoking. When someone inhales cigarette smoke, irritating gases and particles cause one of the
lungs' defenses - the cilia - to slow down. Even one puff on a cigarette slows the cilia, weakening the lungs' ability to defend themselves against infections. Cigarette smoke can cause air passages to close up and make breathing more difficult. It causes chronic inflammation or swelling in the lungs, leading to chronic bronchitis. And cigarette smoke changes the enzyme balance of the lungs, leading to destruction of lung tissue that occurs in emphysema. Macrophages-scavenger cells in the lung-are also harmed.
- 2. Triggers of Asthma - Asthma, the temporary blocking of the small air passages of the lungs, has many possible triggers and can be life-threatening. Infections, lung irritants, cold weather, allergies, over-exertion, excitement, inherited factors, even workplace chemicals and other irritants play a part in this disease.
- 3. Tuberculosis (TB) - Tuberculosis is caused by a bacterium spread by the coughing or sneezing of a person who has active TB germs in his or her mucus (sputum). Many people who develop TB today were infected years ago when the disease was more widespread.
Years or decades later, if the natural defense systems of people's bodies begin to weaken, the barriers they built up around the germs begin to crumble, and the TB germs escape and multiply. Such latent (waiting-to-attack) infection can become real illness when a person's defenses are weakened by HIV (Human Immunodeficiency Virus) infection or other chronic illnesses such as cancer.
A related problem is that outbreaks of TB involving newly infected people are becoming more common in high-risk populations. These groups include individuals who have limited access to health care. In fact, worldwide, TB has become a major international health concern.
- 4. Occupational Hazards - Substances you breathe at work can cause lung disease, too.
Workers who are exposed to occupational hazards in the air - dusts like those from coal, silica, asbestos, or raw cotton and metal fumes or chemical vapors-can develop lung disease, including occupational asthma.
- 5. Virus, Fungus, Bacterium (other than TB)Hundreds of germs like these are carried in the air at all times. If they are inhaled into the lungs, the germs can cause colds, influenza, pneumonia, and other respiratory infections. When these germs lodge in your lungs, your breathing can be disrupted and you can become ill. Some of these illnesses can be prevented with vaccination.
- 6. Air Pollution - Particles and gases in the air can be a source of lung irritation. Do whatever you can to reduce your exposure to air pollution. Refer to radio or television weather reports or your local newspaper for information about air quality. On days when the ozone (smog) level is unhealthy, restrict your physical activity to early morning or evening because smog is increased in sunlight. When pollution levels are dangerous, limit activities as necessary. People with chronic heart and lung disease should remain indoors.
- Air pollution can be a problem indoors, too. Check your home for irritants that you can control like dust, household chemicals, and cigarette smoke. You may also want to test your home for the presence of the gas, radon, which is the second leading cause of lung cancer.
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How Can You Protect Your Lungs and Prevent Lung Disease?
Controlling and preventing lung disease needs everyone's attention. Learn to recognize the symptoms of lung disease, such as those described in this pamphlet. If you have any of these symptoms, see a doctor as soon as possible.
You, your family members and friends need to protect your lungs. Here's how:
- Don't smoke. Quitting smoking is the best protection you can give your lungs and reduces your risk of lung disease. Your local American Lung Association can help.
- Be honest. Understand that chronic cough, shortness of breath and other lung symptoms are not normal.
- Take action. Bring any lung disease symptom to a doctor's attention early. Then follow the doctor's advice.
- Avoid lung hazards. Secondhand cigarette smoke, air pollution, and lung hazards at work can cause lung disease.
- Think about prevention. Lung disease like influenza and pneurnococcal pneumonia can be prevented with vaccination. Get immunized if you are in a high-risk group, which includes people over 65 or anyone with a chronic health problem such as lung disease, heart disease, and diabetes.
Remember - early detection of lung disease is the key to prompt and successful treatment. If you would like more information about the lungs and the prevention of lung disease, contact your local American Lung Association by calling 1-800-LUNGUSA. The American Lung Association has more information about lung disease and related topics including:
Tuberculosis, Cigarette Smoking, Asthma, Nicotine Dependence, Emphysema, Secondhand Smoke, Chronic Bronchitis, Occupational Lung Hazards, Influenza, Pneumonia, Air Pollution from "Facts about How to Keep Your Lungs Healthy", American Lung Association,
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