How Does Asthma Affect Breathing? ( COURTECY;- MEDICINENET.COM
)
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Asthma is a chronic lung disorder that can make breathing
difficult
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What Is Asthma?
Definition
Asthma is a chronic lung
disorder that can make breathing difficult by narrowing and inflaming the
airways (bronchial tubes).
“Asthma” is an ancient
Greek word meaning “short breath, panting.” One of the telltale signs of asthma
attacks is the wheezing and breathing difficulty that they cause.
Asthma attacks can be a
frightening experience, and affect breathing by causing
·
inflammation, swelling,
and narrowing of the airways,
·
recurring wheezing,
·
chest tightness,
·
coughing, and
·
shortness of breath.
Chronically inflamed
bronchial tubes become very sensitive to inhaled allergens or irritants such as
·
pollen,
·
pollution,
·
tobacco smoke, or
·
triggers such as
exercise.
Prevalence of Asthma
About 25 million people
in the U.S. have asthma; 7 million of those are children. Asthma reports are on
the rise. The condition affects men and women equally. Asthma causes over 14
million visits to doctors each year and nearly 2 million visits to emergency
departments.
Asthma Can Be Deadly
Asthma can kill. The
rate of asthma deaths spiked from 2,600 in 1979 up to 4,600 in 1988. The
reasons for this spike are unknown, but may be related to
·
inadequate medical care,
·
an increased severity of
asthma, and/or
·
an increase in the
number of people with asthma.
African Americans are
about three times as likely to die from asthma as white Americans. Most people
who die from asthma are over age 50, but children sometimes die of the
condition, too.
Asthma Inhalers &
Nebulizers
Asthma inhalers and
nebulizers have advantages over oral medications and injections in that they
deliver medicine directly to the airways. They also have fewer side effects
than other forms of asthma medication.
Asthma Inhalers
The most common treatment
for asthma involves a device called an inhaler. An inhaler is a small device
that delivers asthma medicine directly to the airways. Inhalers come in two
types:
·
Metered Dose Inhalers
(MDI): MDIs are the most common type of inhaler. They spray medicine from the
inhaler like an aerosol can.
·
Dry powder inhalers: Dry
powder inhalers deliver a powdered medicine that does not spray from the
inhaler. Instead, the user must breathe in the medicine quickly and forcefully.
Spacers
Sometimes MDIs are used
along with a device called a spacer. Spacers help coordinate breathing with the
release of the asthma medicine, and also make the droplets of medicine smaller,
making it easier to breath them in.
Nebulizers
For babies and very
young children, an inhaler requires too much work. In that case, a nebulizer
can be used. Nebulizers are powered by electricity to turn asthma medicine into
a fine mist. The mist is delivered through a tube attached to a facemask or
mouthpiece. Disadvantages to nebulizers include the fact that they can be
noisy, they can be big, they can be time-consuming, and they may not be very
portable.
Asthma Medications for
Inhalers & Nebulizers
CCommon medications used
with inhalers and nebulizers include the following:
·
Inhaled Corticosteroids:
Inhaled corticosteroids reduce inflammation in the airways, which reduces
swelling and tightening. Sometimes these medicines are used even without asthma
symptoms, as they can help prevent future asthma attacks. Types of inhaled corticosteroids
include beclomethasone, budesonide, ciclesonide, flunisolide, fluticasone, and
triamcinolone.
·
Short-Acting
Bronchodilators: Bronchodilators have no steroids and work by relaxing the tiny
muscles that can tighten airways during asthma attacks. Short-acting
bronchodilators give quick relief to asthma symptoms. Types of short-acting
bronchodilators include albuterol, levalbuterol, terbutaline, and ipratropium.
·
Long-Acting
Bronchodilators: Long-acting bronchodilators are taken daily to help control
asthma and prevent future asthma attacks. Types of long-acting bronchodilators
include salmeterol and formoterol.
The Respiratory System: What Is Respiration?
Respiration
is how our bodies allow oxygen in, and also how our bodies releases carbon
dioxide.
When
we inhale, air passes into our windpipe (trachea), our diaphragm contracts and
moves downward creating air space in our chest cavity. The air enters the
lungs, passing through the bronchial tubes and finally to the air sacs
(alveoli).
Oxygen
from the air passes from the alveoli and into the bloodstream through tiny
blood vessels called capillaries. Capillaries deliver this oxygen-rich blood to
the pulmonary veins, which go to the left side of the heart. The heart then
pumps the oxygen-rich blood to the rest of the body.
When
you exhale, air that is rich in carbon dioxide (CO2) passes out of your lungs,
through the windpipe, and out your nose or mouth.
How Does Asthma Affect
Breathing?
When a person has
asthma, the airways become inflamed and sensitive. This swelling narrows the
airways, making breathing difficult, and often leading to panting and gasping
fits. Three factors cause this narrowing and will be discussed in the following
slides:
·
Inflammation
·
Bronchospasm
·
Hyperreactivity (Asthma
Triggers)
What Causes Asthma? Inflammation
The
main cause of narrowing airways in asthma is inflammation, which makes airways
more swollen and sensitive. When airways are inflamed, air has a smaller space
to pass through. In addition, the muscles surrounding the airways may tighten
during an asthma attack, further narrowing the space for airflow.
When
airways react to inflammation, they also produce more mucus, which is a sticky
and thick liquid substance that can clump together and narrow air passages even
further.
Moreover,
certain allergy and inflammation cells (eosinophils and white blood cells)
accumulate at the site of the inflammation, causing tissue damage and even more
narrow airways.
This
chain reaction causes the breathing difficulty associated with an asthma
attack.
What Causes Asthma?
Bronchospasm
The lungs are made up of
tubes that branch out like a tree. They become smaller and smaller as they
enter the lungs, eventually becoming so small that they become microscopic. The
larger tubes that split off from the trachea into the lungs are called bronchi.
During an asthma attack,
people may experience bronchospasm, where the bronchial tubes tighten and
further narrow the airways. Coughing and wheezing may be symptoms of
bronchospasm, and bronchospasm can occur when the airways are irritated by cold
air.
Bronchospasm can happen
suddenly. It can be treated by medicines called bronchodilators.
·
Which Triggers Cause an Asthma Attack?
Things
that can cause an asthma attack are referred to as "triggers." Not
everyone with asthma has the same triggers. Triggers can be either allergens or
irritants. People with asthma need to learn what their triggers are so the
triggers can be managed or avoided altogether.
Recognizing
and avoiding your triggers can help you prevent further asthma attacks.
Allergists and immunologists are medical doctors who specialize in helping
patients identify irritants and allergies that cause problems like asthma. They
can help you develop a plan to avoid asthma triggers and feel better more
consistently.
Asthma Triggers:
Allergens
Asthma can have both
allergic and nonallergic triggers. Allergic asthma triggers include many
allergens. Some of these allergens include
·
pollen,
·
dust,
·
mold,
·
pets,
·
common foods including
peanuts, egg, dairy, soy, and fish,
·
sulfites, and
·
latex.
Asthma Triggers:
Allergens
Asthma can have both
allergic and nonallergic triggers. Allergic asthma triggers include many
allergens. Some of these allergens include
·
pollen,
·
dust,
·
mold,
·
pets,
·
common foods including
peanuts, egg, dairy, soy, and fish,
·
sulfites, and
·
latex.
·
Asthma Triggers:
Irritants
Nonallergic asthma
triggers include irritants such as:
·
tobacco smoke,
·
viral upper respiratory
infections,
·
environmental pollutants
such as smog or vehicle fumes,
·
indoor irritants such as
perfumes, detergents, and paints,
·
exercise,
·
work-related exposure to
chemicals, dusts, and gases,
·
drugs such as aspirin or
NSAIDs (nonsteroidal anti-inflammatory drugs), and beta-blockers, and
·
GERD (gastroesophageal
reflux disorder).
Asthma Symptoms in Adults and Kids
Asthma
seems to have both genetic and environmental causes, and can develop at any
age. However, asthma does tend to start in children ages 2-6. At this age,
asthma is triggered by allergens such as dust mites, tobacco smoke, and viral
upper respiratory infections.
Adults
can also develop asthma, and only about 30% of adult asthma triggers are
related to allergies such as pet dander, mold, or dust mites. Risk factors for
adult-onset asthma include being female, obesity, hormonal fluctuations such as
those experienced during or after pregnancy or menopause, and viral or other
infections.
Types of Asthma: Allergic (Extrinsic)
Allergic
(extrinsic) asthma is that which is triggered by an allergic reaction. It is an
immune system response to an irritant. This is the most common form of asthma,
affecting more than half of all sufferers. It can often be managed with
medication.
Types of Asthma: Non-Allergic (Intrinsic)
Non-allergic
(intrinsic) asthma is caused by factors other than allergies, such as exercise,
stress or anxiety, inhaling cold air, smoke, viral infections, and other
irritants. This type of asthma is less common, it develops more often in
adults, and is more difficult to treat than allergic (extrinsic) asthma.
Symptoms and Signs of
Asthma
Symptoms of asthma, both
allergic and non-allergic, include
·
shortness of breath,
·
wheezing,
·
coughing, and
·
chest tightness.
Not everyone with asthma
will experience all symptoms, and the severity of symptoms can vary depending
on the individual—even in an individual they may vary over time.
Asthma: Mild to Severe
The National Asthma
Education and Prevention Program classifies asthma based on a patient's
symptoms and lung function tests into these four categories:
·
Intermittent
·
Mild persistent
·
Moderate persistent
·
Severe persistent
Asthma: Mild to Severe
The National Asthma
Education and Prevention Program classifies asthma based on a patient's
symptoms and lung function tests into these four categories:
·
Intermittent
·
Mild persistent
·
Moderate persistent
·
Severe persistent
Acute Asthma Attack
An "asthma
attack" is an acute worsening of asthma symptoms. During an acute asthma
attack, there is
·
inflammation,
·
bronchospasm, and
·
mucus produced,
leading to symptoms such
as
·
difficulty breathing,
·
shortness of breath,
·
wheezing,
·
coughing, and
·
interference with daily
activities.
Many times asthma
attacks can be controlled with inhalers (inhaled bronchodilators). If that is
ineffective, the patient should call 911 or be taken to an emergency room immediately.
When asthma does not respond to initial treatment it can result in a
life-threatening reaction called status asthmaticus.
Asthma Exams & Tests
·
lung (pulmonary)
function tests, including spirometry and or peak flow meter tests, measure lung
function,
·
blood tests measure
levels of IgE, which are antibodies released during allergic reactions,
·
bronchoprovocation
measures how sensitive your airways are,
·
tests to rule out other
conditions such as reflux disease or sleep apnea, and
·
chest x-rays or EKGs to
find out if a foreign object or another condition is causing your symptoms.
Medical Treatment of
Asthma
Asthma medications are
classified as either for long-term control, or quick relief. Most are inhaled
rather than taken in tablet or liquid form, to act directly on the airways
where the breathing problems start.
Long-term control
medications include:
·
Inhaled corticosteroids
·
Cromolyn, taken using a
nebulizer
·
Omalizumab (anti-IgE),
given as an injection
·
Inhaled short-acting
beta2-agonists
·
Leukotriene modifiers,
taken by mouth
·
Theophylline, taken by
mouth
Quick-relief medications
include:
·
Inhaled long-acting
beta2-agonists
Asthma At A Glance
·
Asthma is a chronic lung
disorder that can make breathing difficult. It causes inflammation, swelling,
and narrowing of the airways (bronchial tubes).
·
About 25 million people
in the U.S have asthma; 7 million of those are children.
·
Asthma involves narrowing
of the airways caused by three major factors: inflammation, bronchospasm, and
hyperreactivity.
·
Allergy plays a role in
some, but not all, asthma patients.
·
Allergens and irritants
can cause asthma attacks.
·
Asthma symptoms include
shortness of breath,
·
Asthma is diagnosed
based physical exam, patient history, and confirmed with breathing tests.
·
The best way to manage
asthma is to try to avoid triggers such as allergens or irritants.
·
Medications can reverse
or prevent bronchospasm in patients with asthma.
·
Reviewed by William C. Shiel Jr., MD, FACP, FACR on Saturday, October 29, 2016
Reviewed by William C. Shiel Jr., MD, FACP, FACR on Saturday, October 29, 2016
·
Asthma Symptoms, Causes,
and Medications
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Sources: 
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This tool does not
provide medical advice
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