Information
for this section from: Facts in Brief About Lung Disease, American
Lung Association, 6/91; Lung Disease Data 1995, American Lung
Association, 1995; Mayo Clinic Family Health Book, William Morrow
and Company, Inc., New York, 1990.
Other
lung disease facts
- Lung
disease and breathing problems are the number one cause of death
for babies under one year old, accounting for about 33% of infant
deaths.
- The
lung is a major target of infection in people with AIDS.
- Lung
disease is the number one disabler of American workers.
- Lung
disease strikes people of all ages and races, but the overall
lung disease death rate for black Americans is 20.4 % higher
than for whites.
- Acute
respiratory diseases account for 61% of school absenteeism attributed
to acute conditions.
- Cigarette
smoking is the major cause of emphysema and chronic bronchitis.
- Americans
spend almost 420 million days in bed each year due to acute
respiratory conditions such as influenza (flu) and the common
cold.
How
the lungs work
Lungs
provide oxygen to your blood and remove carbon dioxide from it.
They are located within your chest and are protected on the sides,
back and front by your ribs and the cartilage and muscle between
them. Your diaphragm separates your chest cavity from your abdomen.
Your heart is between your lungs, located over one corner of the
left lung.
Soft
and spongy, healthy lungs are a mottled pinkish gray color. Your
right lung is divided into three sections (lobes), while your
left lung has two. When you inhale, air enters through your mouth
and nose, travels through the back of your throat (pharynx), through
your voice box (larynx), and down your windpipe (trachea). Like
an upside-down tree, the trachea branches into two main tubes,
then each tube branches into smaller passageways (bronchi) which
continue dividing and eventually form much smaller tubes (bronchioles).
The smallest bronchioles end in tiny air sacs called alveoli,
where the oxygen in the air you just inhaled transfers to your
blood located in capillaries lining the alveoli. At the same time,
the carbon dioxide in the capillaries is released. This is called
gas exchange.
Your
heart is located next to your lungs for a very good reason ---
teamwork! After oxygen is released into your blood, the blood
is pumped through pulmonary vessels and veins back to the heart.
Oxygen-rich blood is then pumped out of the heart to deliver oxygen
to the cells in your body and to remove carbon dioxide.
Your
heart then pumps the blood back to your heart's right ventricle
(bottom right amber) through the pulmonary artery to your lungs.
Similar to the airways, the pulmonary arteries form smaller and
smaller vessels down to the capillaries, which are so tiny that
the blood cells pass through single file.
Diagnosing
lung disease
If
you have early warning signs of lung disease such as shortness
of breath or fatigue, talk to your doctor about diagnosing the
problem with a pulmonary function test. These tests can assess
the severity of functional impairment, determine your suitability
for certain jobs or activities, and follow the progress of the
disease and its response to treatment and cardiopulmonary rehabilitation.
Commonly
performed pulmonary function tests include measurements of lung
volumes, forced expiratory flow rates (how fast you can blow the
air out of your lungs), slow vital capacity (how much air you
can move with your lungs), diffusing capacity (how well your lungs
perform gas exchange), and maximum inspiratory and expiratory
pressures (an overall measure of respiratory muscle strength).
In addition, cardiopulmonary exercise testing is often performed
to measure maximum oxygen consumption and anaerobic threshold.
Testing
techniques include spirometry, pulmonary function, plethysmography,
and cardiopulmonary exercise testing.
Spirometry
In
the spirometry procedure, you will breath through a device called
a spirometer that will measure and record the amount of air you
exhaled and the rate of air passage for a specific time period.
As you will need to take the deepest breath you can and exhale
for as long as you can, the results of this test depend on your
effort. The information will be displayed on a computer screen
as a volume versus time curve or a flow versus volume curve. Your
health care provider will interpret this curve to detect any abnormalities
in the large or small airways of your lungs.
Pulmonary
function testing
A
pulmonary function testing system will perform spirometry as described
above as well as measurements of your lung volumes and bronchial
provocation (measurements of your lungs before and after you inhale
an agent used to provoke your lungs). As in spirometry, the results
of these tests are dependent upon your effort.
Body
plethysmography
Body
plethysmographs are airtight, transparent chambers in which patients
sit inside and breathe on a mouthpiece. The "body box"
--- as pulmonary specialists call it --- measure the pressure
changes inside the box as your chest cavity moves with breathing
to determine the total amount of volume inside your lungs. Another
measurement is called airways resistance, which is basically measuring
how much pressure it takes to push air through your airways. It
detects even the smallest changes in your lungs. Because of its
superior sensitivity to changes in your airways, plethysmography
is considered the most accurate way to diagnose lung diseases
such as asthma which react to substances or other triggers.
Cardiopulmonary
exercise testing
Although
all the previous mentioned tests are frequently adequate for detecting
cardiorespiratory problems, these tests are performed while you
are sitting quietly. Thus, they may not detect problems with your
cardiorespiratory system that occur during activity. However,
cardiopulmonary exercise testing (sometimes also called gas exchange
testing) can detect symptoms during exercise. These systems vary
in features but generally require you to take a standard stress
test on a treadmill or bicycle while breathing through a mouthpiece
that measures the amount of oxygen you are consuming and carbon
dioxide you are exhaling. Because it measures how well your heart,
lungs, blood vessels, and muscles are working together, it is
a comprehensive and global test to detect early warning signs
of heart or lung disease.
Beware
of infection
The
mouthpieces, tubing and other air spaces in pulmonary testing
equipment is a perfect environment for microorganisms to grow.
Be sure your health care provider uses equipment with disposable
mouthpieces, pneumotachs, filters, nose clips, and breathing circuits.
If he or she does not use a disposable pneumotach, be sure they
are following proper cleaning procedures according to the manufacturer's
instructions.
Lung
diseases
Lung
cancer
Lung
cancer is the most common fatal cancer in the U.S., and has increased
in recent years more than any other malignancy. The number one
cause of lung cancer is cigarette smoking, which is responsible
for 87% of lung cancer cases. Other causes of lung cancer are
second-hand smoke, radon, industrial substances such as asbestos,
and other airborne toxins. If found early, treatment --- surgery,
radiation, drug therapy, or a combination of these --- may be
effective.
Chronic
Obstructive Pulmonary Disease (COPD)
Two
lung diseases fall under the category of COPD: bronchitis and
emphysema. Both conditions are largely caused by smoking and often
occur together.
Bronchitis
Bronchitis
affects 13.5 million Americans and is the sixth-ranking chronic
condition in the country. Bronchitis is an inflammation of the
lining of the bronchial tubes that connect the windpipe to the
lungs. When the lining is inflamed, excess mucus is secreted and
airflow to the lungs is disrupted. You will need to cough to get
rid of the mucus and unclog the tubes. A persistent cough, however,
may be a symptom of chronic bronchitis and demands medical attention.
Too many people dismiss this disease as a "cigarette cough"
and do not seek treatment.
In
fact, the leading cause of bronchitis is cigarette smoking. To
avoid chronic bronchitis, you must eliminate the source of irritation
and infection, such as quitting smoking. Chronic bronchitis is
often accompanied by emphysema.
Emphysema
Emphysema
is a severe lung disease that develops gradually over a period
of time. It affects about 1.9 million Americans, most of whom
have been smokers for years. Portions of the lungs become so damaged
they will not expand or contract with breathing. The lungs become
rigid with trapped gases in the alveoli that cannot escape. Because
the lungs are not efficient in exchanging oxygen and carbon dioxide,
the heart has to work harder and becomes damaged. The damage is
irreversible, and death due to heart disease is often the result
of emphysema.
Treatment
options include lung transplantation and lung reduction surgery,
a new procedure during which the damaged portions of the patient's
lungs are surgically removed. Efforts are underway in the medical
community to decide upon a standard set of criteria for selection
of candidates for lung reduction surgery, but most experts agree
it should include a body plethysmography test to determine the
amount of trapped gas in the lungs.
Tuberculosis
(TB)
Once
thought to be a disease of the past, tuberculosis is increasing
at an alarming rate in the U.S. due to the AIDS epidemic, spread
of TB among the homeless, and drug resistance. Tuberculosis is
caused by an airborne germ called tubercle bacillus. Anyone can
breathe in TB germs, which are spread by coughing or sneezing
from a person carrying the germ. Symptoms of TB are coughing often,
feeling tired, an unexplained loss of appetite, and weight loss.
Spitting up blood is a symptom of well-developed disease. TB is
treated by medication. People at higher risk for developing TB
are those with weakened immune defenses, such as those with HIV
infection.
Asthma
Click
here to link to our asthma section.
Occupational
lung diseases
People
who are exposed to particles in the air such as coal dust and
asbestos fibers are at risk for developing occupational lung diseases
called pneumoconiosis, including the following:
- Occupational
asthma: Dusts and chemicals at the worksite may trigger an asthma
attack.
- The
most effective treatment of occupational asthma is to avoid
the substance triggering the attack. Episodes may also be treated
by bronchodilator drugs and corticosteriods.
- Black
lung: This lung disease is a common name for coal worker's pneumoconiosis,
caused by exposure to coal dust over many years. The result
is impaired lung function.
- Asbestosis:
This lung disease is caused by inhaling asbestos fibers, which
irritate the lungs and cause thickening of the walls of the
lung's alveoli. Lung cancer may be a result of asbestosis, especially
if the worker also smokes. Workers may not show signs of disease
for 30 years or more after exposure to asbestos.
- Silicosis:
Breathing silica dust, such as that found in rock, granite and
marble industries, cause this lung disease.
- Berylliosis:
A disease of the lungs caused by inhaling dust from the metal
beryllium usedin nuclear reactors and missile systems.
Major
acute pulmonary infections (influenza and pneumonia)
People
at risk for pulmonary infections are those with weakened immune
systems, such as the very young, very old, those with chronic
respiratory or circulatory problems, and those with weakened immune
systems from congenital deficiencies, medications and AIDS.
Influenza
(flu) in the U.S. generally strikes between December and March.
It is caused by a virus, and its symptoms may include fever, headache,
cough, sore throat, runny nose, muscle aches, and general malaise.
The American Lung Association recommends all persons over age
65 receive an influenza vaccination in advance of the expected
flu season, as well as anyone else at risk. Updates on flu outbreaks
are available from October through May on the Center for Disease
Control's interactive voice information system at (404) 332-4555.
The phone is open Monday through Friday from 8:00 am to 4:30 pm
Eastern time.
Pneumonia
has symptoms including coughing with a lot of sputum, fever, chills,
and chest pain. Vaccinations against pneumococcal pneumonia is
recommended for people over age 65, adults with chronic illness,
children at risk over age two, and those with HIV infection.
Respiratory
distress syndrome (RDS)
Respiratory
distress syndrome is a life-threatening situation that occurs
in premature babies whose lungs are not fully developed and cannot
breathe without assistance. The mature lung contains a fluid called
surfactant that is essential for the expansion and contraction
of the alveoli in the lungs. A baby born prematurely may not have
this fluid, and its lungs cannot inflate. In recent years, replacement
surfactants have been developed that have significantly reduced
the mortality rate due to RDS.
Adult
(acute) respiratory distress syndrome (ARDS)
Adult
respiratory distress syndrome is extensive pulmonary inflammation,
small blood vessel injury, and progressive malfunction of the
lungs and other organs due to inadequate oxygenation.
Fluid
fills the lungs and the alveoli collapse. Acute respiratory distress
syndrome may occur in children as well. ARDS is typically caused
by severe trauma or massive, uncontrolled infection, and has a
mortality rate of 50 percent.
Cystic
fibrosis (CF)
Cystic
fibrosis is a hereditary disorder that occurs about once in every
3,500 births. CF causes the production of abnormally thick and
viscous mucus that obstructs a number of the body's tracts. CF
affects the pancreatic ducts, which prevents normal digestion
and leads to malabsorption and malnutrition. In 90 percent of
cases, the airways are also affected. Children with CF are highly
susceptible to lung infections, and the chronic lung dysfunction
can cause severe debilitation and may lead to pulmonary hypertension
and heart disease. Treatment of CF has improved greatly over the
past 25 years, including antibiotics to ward off infection and
bronchodilators to help treat the airways. The specific gene that
causes the disease was identified in 1989, and experimental gene
therapy to cure individual patients is underway in both the U.S.
and Great Britain.
Sudden
infant death syndrome (SIDS)
SIDS
is the second leading cause of infant death, causing about 5,000
fatalities every year. It is the sudden death of an apparently
healthy infant whose heartbeat and breathing stop. The cause is
unknown, but some experts believe it is caused by an infectious
agent, a severe allergic reaction, or suffocation. The American
Academy of Pediatrics and the National Institutes of Health recommend
placing sleeping babies on their backs or sides and to avoid thick,
soft, fluffy bedding materials that can cover the nose and mouth
of an infant. Maternal smoking before and after the child's birth
has also been linked to SIDS.
Obstructive
sleep apnea
Obstructive
sleep apnea is a breathing disorder in which the upper airway
frequently collapses during sleep. This results in cycles of subconscious
awakenings that, in severe cases, can occur several hundred times
a night. Suffers of sleep apnea experience excessive daytime sleepiness
or reduced cognitive function such as memory loss and lack of
concentration. They may also experience oxygen desaturation, an
increase in heart rate, and elevated blood pressure during the
apnea episode. Sleep apnea has also been associated with increased
risk of cardiovascular morbidity and mortality due to angina,
stroke and heart attack, and accidents caused by excessive daytime
sleepiness.
The
National Commission on Sleep Disorders Research estimates that
about 20 million people in the U.S. suffer from sleep apnea, yet
less than 3% of those afflicted know the cause of their fatigue
or other symptoms. There are over 1500 sleep disorders clinics
in the U.S., which have "sleep labs" to diagnose this
disease. Treatment is a technique called nasal continuous positive
airway pressure (CPAP), which delivers air and/or oxygen through
a mask while the patient sleeps.
Lung
disease links
American
Association for Respiratory Care
The national association for respiratory care practitioners
American
Lung Association/American Thoracic Society
Information and programs on lung health, disorders and research
American
Medical Association
Information about a wide range of medical issues
Mesothelioma
Lung Cancer information updates
News and information about mesothelioma and treatment options
for the disease. This site also provides news about asbestos-related
legislation, regulations, and other topics related to asbestos
exposure.
