What Is Asthma?
Asthma (Az-muh) is a chronic disease that affects
your airways. The airways are the tubes that carry air in and out of your
lungs. If you have asthma, the inside walls of your airways are inflamed
(swollen). The inflammation (IN-fla-MAY-shun) makes the airways very sensitive,
and they tend to react strongly to things that you are allergic to or find
irritating. When the airways react, they get narrower, and less air flows
through to your lung tissue. This causes symptoms like wheezing (a whistling
sound when you breathe), coughing, chest tightness, and trouble breathing,
especially at night and in the early morning.
Asthma cannot be cured, but most people with asthma
can control it so that they have few and infrequent symptoms and can live
active lives.
When your asthma symptoms become worse than usual,
it is called an asthma episode or attack. During an asthma attack, muscles
around the airways tighten up, making the airways narrower so less air flows
through. Inflammation increases, and the airways become more swollen and even
narrower. Cells in the airways may also make more mucus than usual. This extra
mucus also narrows the airways. These changes make it harder to breathe.
Asthma attacks are not all the samesome are
worse than others. In a severe asthma attack, the airways can close so much
that not enough oxygen gets to vital organs. This condition is a medical
emergency. People can die from severe asthma attacks.
So, if you have asthma, you should see your doctor
regularly. You will need to learn what things cause your asthma symptoms and
how to avoid them. Your doctor will also prescribe medicines to keep your
asthma under control.
Taking care of your asthma is an important part of
your life. Controlling it means working closely with your doctor to learn what
to do, staying away from things that bother your airways, taking medicines as
directed by your doctor, and monitoring your asthma so that you can respond
quickly to signs of an attack. By controlling your asthma every day, you can
prevent serious symptoms and take part in all activities.
If your asthma is not well controlled, you are
likely to have symptoms that can make you miss school or work and keep you from
doing things you enjoy. Asthma is one of the leading causes of children missing
school.
What Causes Asthma?
It is not clear exactly what makes the airways of
people with asthma inflamed in the first place. Your inflamed airways may be
due to a combination of things. We know that if other people in your family
have asthma, you are more likely to develop it. New research suggests that
being exposed to things like tobacco smoke, infections, and some allergens
early in your life may increase your chances of developing asthma.
What Causes Asthma Symptoms and Attacks?
There are things in the environment that bring on
your asthma symptoms and lead to asthma attacks. Some of the more common things
include exercise, allergens, irritants, and viral infections. Some people have
asthma only when they exercise or have a viral infection.
The list below gives some examples of things that
can bring on asthma symptoms.
Allergens
- Animal dander (from the skin, hair, or feathers
of animals)
- Dust mites (contained in house dust)
- Cockroaches
- Pollen from trees and grass
- Mold (indoor and outdoor)
Irritants
- Cigarette smoke
- Air pollution
- Cold air or changes in weather
- Strong odors from painting or cooking
- Scented products
- Strong emotional expression (including crying or
laughing hard) and stress
Others
- Medicines such as aspirin and beta-blockers
- Sulfites in food (dried fruit) or beverages
(wine)
- A condition called gastroesophageal
(GAS-tro-e-sof-o-JEE-al) reflux disease that causes heartburn and can worsen
asthma symptoms, especially at night
- Irritants or allergens that you may be exposed to
at your work, such as special chemicals or dusts
- Infections
This is not a complete list of all the things that
can bring on asthma symptoms. People can have trouble with one or more of
these. It is important for you to learn which ones are problems for you. Your
doctor can help you identify which things affect your asthma and ways to avoid
them.
Who Is At Risk for Asthma?
In the United States, about 20 million people have
been diagnosed with asthma; nearly 9 million of them are children.
Asthma is closely linked to allergies. Most, but not
all, people with asthma have allergies. Children with a family history of
allergy and asthma are more likely to have asthma.
Although asthma affects people of all ages, it most
often starts in childhood. More boys have asthma than girls, but in adulthood,
more women have asthma than men.
Although asthma affects people of all races, African
Americans are more likely than Caucasians to be hospitalized for asthma attacks
and to die from asthma.
What Are the Signs and Symptoms of Asthma?
Common asthma symptoms include:
- Coughing. Coughing from asthma is often worse at
night or early in the morning, making it hard to sleep.
- Wheezing. Wheezing is a whistling or squeaky
sound when you breathe.
- Chest tightness. This can feel like something is
squeezing or sitting on your chest.
- Shortness of breath. Some people say they can't
catch their breath, or they feel breathless or out of breath. You may feel like
you can't get enough air in or out of your lungs.
- Faster breathing or noisy breathing.
Not all people have these symptoms, and symptoms may
vary from one asthma attack to another. Symptoms can differ in how severe they
are: Sometimes symptoms can be mildly annoying, other times they can be serious
enough to make you stop what you are doing, and sometimes symptoms can be so
serious that they are life threatening.
Symptoms also differ in how often they occur. Some
people with asthma have symptoms only once every few months, others have
symptoms every week, and still other people have symptoms every day. With
proper treatment, however, most people with asthma can expect to have few or no
symptoms.
How Is Asthma Diagnosed?
Some things your doctor will ask about include:
- Periods of coughing, wheezing, shortness of
breath, or chest tightness that come on suddenly, occur often, or seem to
happen during certain times of the year or season
- Colds that seem to "go to the chest" or take more
than 10 days to get over
- Medicines you may have used to help your
breathing
- Your family history of asthma and allergies
- Things that seem to cause your symptoms or make
them worse
Your doctor will listen to your breathing and look
for signs of asthma or allergies.
Your doctor will probably use a device called a
spirometer (speh-ROM-et-er) to check how your lungs are working. This test is
called spirometry (speh-ROM-eh-tree). The test measures how much air you can
blow out of your lungs after taking a deep breath, and how fast you can do it .
The results will be lower than normal if your airways are inflamed and
narrowed, or if the muscles around your airways have tightened up.
As part of the test, your doctor may give you a
medicine that helps open narrowed airways to see if the medicine changes or
improves your test results.
Spirometry is also used to check your asthma over
time to see how you are doing.
Spirometry usually cannot be used in children
younger than 5 years. If your child is younger than 5 years, the doctor may
decide to try medicine for a while to see if the child's symptoms get better.
If your spirometry results are normal but you have
asthma symptoms, your doctor will probably want you to have other tests to see
what else could be causing your symptoms.
These include:
- Allergy testing to find out if and what allergens
affect you.
- A test in which you use a peak flow meter every
day for 1-2 weeks to check your breathing. A peak flow meter is a hand-held
device that helps you monitor how well you are breathing.
- A test to see how your airways react to exercise.
- Tests to see if you have gastroesophageal reflux
disease.
- A test to see if you have sinus disease.
Other tests, such as a chest x ray or an
electrocardiogram, may be needed to find out if a foreign object or other lung
diseases or heart disease could be causing your symptoms. A correct diagnosis
is important because asthma is treated differently from other diseases with
similar symptoms.
Depending on the results of your physical exam,
medical history, and lung function tests, your doctor can determine how severe
your asthma is. This is important because the severity of your asthma will
determine how your asthma should be treated. One way for doctors to classify
asthma severity is by considering how often you have symptoms when you are not
taking any medicine or when your asthma is not well controlled.
Based on symptoms, the four levels of asthma
severity are:
- Mild intermittent (comes and goes)you have
episodes of asthma symptoms twice a week or less, and you are bothered by
symptoms at night twice a month or less; between episodes, however, you have no
symptoms and your lung function is normal.
- Mild persistent asthmayou have asthma
symptoms more than twice a week, but no more than once in a single day. You are
bothered by symptoms at night more than twice a month. You may have asthma
attacks that affect your activity.
- Moderate persistent asthmayou have asthma
symptoms every day, and you are bothered by nighttime symptoms more than once a
week. Asthma attacks may affect your activity.
- Severe persistent asthmayou have symptoms
throughout the day on most days, and you are bothered by nighttime symptoms
often. In severe asthma, your physical activity is likely to be limited.
Anyone with asthma can have a severe
attackeven people who have intermittent or mild persistent asthma.
How Is Asthma Treated?
Your doctor can work with you to decide about your
treatment goals and what you need to do to control your asthma to achieve these
goals. Asthma treatment includes:
- Working closely with your doctor to decide what
your treatment goals are and learning how to meet those goals.
- Avoiding things that bring on your asthma
symptoms or make your symptoms worse. Doing so can reduce the amount of
medicine you need to control your asthma.
- Using asthma medicines. Allergy medicine and
shots may also help control asthma in some people.
- Monitoring your asthma so that you can recognize
when your symptoms are getting worse and respond quickly to prevent or stop an
asthma attack.
With proper treatment, you should ideally have these
results:
- Your asthma should be controlled.
- You should be free of asthma symptoms.
- You should have fewer attacks.
- You should need to use quick-relief medicines
less often.
- You should be able to do normal activities
without having symptoms.
Your doctor will work with you to develop an asthma
self-management plan for controlling your asthma on a daily basis and an
emergency
action
plan for stopping asthma attacks. These plans will tell you what medicines
you should take and other things you should do to keep your asthma under
control.
Medicines for Asthma
There are two main types of medicines for asthma:
- Quick-relief medicinestaken at the first
signs of asthma symptoms for immediate relief of these symptoms. You will feel
the effects of these medicines within minutes.
- Long-term control medicinestaken every day,
usually over long periods of time, to prevent symptoms and asthma episodes or
attacks. You will feel the full effects of these medicines after taking them
for a few weeks. People with persistent asthma need long-term control
medicines.
Quick-relief medicines
Everyone with asthma needs a quick-relief or
"rescue" medicine to stop asthma symptoms before they get worse. Short-acting
inhaled beta-agonists are the preferred quick-relief medicine. These medicines
are bronchodilators. They act quickly to relax tightened muscles around your
airways so that the airways can open up and allow more air to flow through.
You should take your quick-relief medicine when you
first begin to feel asthma symptoms, such as coughing, wheezing, chest
tightness, or shortness of breath. You should carry your quick-relief inhaler
with you at all times in case of an asthma attack.
Your doctor may recommend that you take your
quick-relief medicines at other times as wellfor example, before
exercise.
Long-term control medicines
The most effective, long-term control medicine for
asthma is an inhaled corticosteroid (kor-ti-ko-STE-roid) because this medicine
reduces the airway swelling that makes asthma attacks more likely.
Inhaled corticosteroids (or steroids for short) are
the preferred medicine for controlling mild, moderate, and severe persistent
asthma. They are generally safe when taken as directed by your doctor.
In some cases, steroid tablets or liquid are used
for short periods of time to bring asthma under control. The tablet or liquid
form may also be used to control severe asthma.
Other long-term control medicines include:
- Inhaled long-acting beta-agonists. These
medicines are bronchodilators, or muscle relaxers, not anti-inflammatory drugs.
They are used to help control moderate and severe asthma and to prevent
nighttime symptoms. Long-acting beta-agonists are usually taken together with
inhaled corticosteroid medicines.
- Leukotriene modifiers (montelukast, zafirlukast,
and zileuton), which are used either alone to treat mild persistent asthma or
together with inhaled corticosteroids to treat moderate or severe asthma.
- Cromolyn and nedocromil, which are used to treat
mild persistent asthma.
- Theophylline, which is used either alone to treat
mild persistent asthma or together with inhaled corticosteroids to treat
moderate persistent asthma. People who take theophylline should have their
blood levels checked to be sure the dose is appropriate.
If you stop taking long-term control medicines, your
asthma will likely worsen again.
Many people with asthma need both a short-acting
bronchodilator to use when symptoms worsen and long-term daily asthma control
medicines to treat the ongoing inflammation.
Over time, your doctor may need to make changes in
your asthma medicine. You may need to increase your dose, lower your dose, or
try a combination of medicines. Be sure to work with your doctor to find the
best treatment for your asthma. The goal is to use the least amount of medicine
necessary to control your asthma.
Most asthma medicines are inhaled. They go directly
into your lungs where they are needed. There are many kinds of inhalers, and
many require different techniques. It is important to know how to use your
inhaler correctly.
Use a Peak Flow Meter
As part of your daily asthma self-management plan,
your doctor may recommend that you use a hand-held device called a peak flow
meter at home to monitor how well your lungs are working.
You use the peak flow meter by taking a deep breath
in and then blowing the air out hard into the peak flow meter. The peak flow
meter then gives you a peak flow number that tells you how fast you moved the
air out.
You will need to find out your "personal best" peak
flow number. You do this by recording your peak flow number every day for a few
weeks until your asthma is under control. The highest number you get during
that time is your personal best peak flow. Then you can compare future peak
flow measurements to your personal best peak flow, and that will show if your
asthma is staying under control.
Your doctor will tell you how and when to use your
peak flow meter and how to use your medicines based on the results. You may be
advised to use your peak flow meter each morning to keep track of how well you
are breathing.
Your peak flow meter can help warn you of a possible
asthma attack even before you notice symptoms. If your peak flow meter shows
that your breathing is getting worse, you should follow your emergency asthma
action plan. Take your quick-relief or other medicines as your doctor directed.
Then you can use the peak flow meter to see how your airways are responding to
the medicine.
Ask your doctor about how you can take care of your
asthma. You should know:
- What things tend to make your asthma worse and
how to avoid them
- Early signs to watch for that mean your asthma is
starting to get worse (like a drop in your peak flow number or an increase in
symptoms)
- How and when to use your peak flow meter
- What medicines to take, how much to take, when to
take them, and how to take them correctly
- When to call or see your doctor
- When you should get emergency treatment
Treating Asthma in Children
Children with asthma, like adults with asthma,
should see a doctor for treatment of their asthma. Treatment may include
allergy testing, finding ways to limit contact with things that bring on asthma
attacks, and taking medicine.
Young children will need help from their parents and
other caregivers to keep their asthma under control. Older children can learn
to care for themselves and follow their asthma self-management plan with less
supervision.
Asthma medicines for children are like those adults
use, but doses are smaller. Children with asthma may need both a quick-relief
(or "rescue") inhaler for attacks and daily medicine to control their asthma.
Children with moderate or severe asthma should learn to use a peak flow meter
to help keep their asthma under control. Using a peak flow meter can be very
helpful because children often have a hard time describing their symptoms.
Parents should be alert for possible signs of asthma
in children, such as coughing at night, frequent colds, wheezing, or other
signs of breathing problems. If you suspect that your child has asthma or that
your child's asthma is not well controlled, take your child to a doctor for an
exam and testing.
Your doctor will choose medicines for your child
based on the child's symptoms and test results. If your child has asthma, you
will need to go to the doctor for regular followup visits and to make sure that
your child uses the medicines properly.
Treating Asthma in Older Adults
Older adults may need to adjust their asthma
treatment because of other diseases or conditions that they have. Some
medicines (like beta blockers used for treating high blood pressure and
glaucoma; aspirin; and nonsteroidal anti-inflammatory drugs) can interfere with
asthma medicines or even cause asthma attacks. Be sure to tell your doctor
about all medicines that you take, including over-the-counter ones.
Using steroids may affect bone density in adults, so
ask your doctor about taking calcium and vitamin D supplements and other ways
to help keep your bones strong.
Treating Asthma in Pregnancy
If you are pregnant, it is very important to both
you and your baby to control your asthma. Uncontrolled asthma can lower the
oxygen level in your blood, which means that your baby gets less oxygen too.
Most asthma medicines are generally safe to take
during pregnancy. Doctors recommend that it is safer to take asthma medicines
during pregnancy than to take the chance that you will have an attack.
If you are pregnant or thinking about becoming
pregnant, talk to your doctor about your asthma and how to have a healthy
pregnancy.
Treating Exercise-Induced Asthma
Regular physical activity is important for good
health. If exercise brings on your asthma symptoms, talk to your doctor about
the best ways to control your asthma when you are active. Some people with
asthma use inhaled, quick-relief medicines before exercising to keep symptoms
under control.
If you use your asthma medicines as directed, you
should be able to take part in any physical activity or sport you choose. Many
Olympic athletes have asthma.
Can Asthma Be Prevented?
We don't yet know how to prevent asthma, but there
are some things that can lower your chances of having an asthma attack.
To prevent asthma symptoms:
- Learn about your asthma and how to control it.
- Use medicines as directed by your doctor to
prevent or stop attacks.
- Avoid things that make your asthma worse as much
as possible.
- Get regular checkups from your doctor.
- Follow your asthma self-management plan.
Scientists do not yet know how to prevent the
inflammation of the airways that leads to asthma. Scientists are exploring some
theories:
- Babies exposed to tobacco smoke are more likely
to get asthma. If a woman is exposed to tobacco smoke during pregnancy, her
baby may also be more likely to get asthma.
- Obesity may be linked to asthma, as well as other
health problems.
Living With Asthma
If you have asthma, it is important to learn how to
take care of yourself. Work with your doctor on a daily asthma self-management
plan that you are both happy with.
- Tell your doctor about all other medications you
are taking, in case one of them affects your asthma.
- Follow your asthma self-management plan and have
regular checkups.
- Learn to use your medication correctly. Ask your
doctor to teach you how to use your inhaler. This is very important. If you do
not use your inhalers correctly, less medication will get into your airways.
- If you are having problems taking your asthma
medicine, let your doctor know right away.
You need to know what things bring on your asthma
symptoms. Then do what you can to avoid or limit contact with these things.
- If animal dander is a problem for you, keep your
pet out of the house or at least out of your bedroom, or find it a new home.
- Do not smoke or allow smoking in your home.
- If pollen is a problem for you, stay indoors with
the air conditioner on, if possible, when the pollen count is high.
- To control dust mites, wash your sheets,
blankets, pillows, and stuffed toys once a week in hot water. You can get
special dust proof covers for your mattress and pillows.
- If cold air bothers you, wear a scarf over your
mouth and nose in the winter.
- If you have symptoms when you exercise or do
routine physical activities like climbing stairs, work with your doctor to find
ways to be active without having asthma symptoms. Physical activity is
important.
- If you are allergic to sulfites, avoid foods
(like dried fruit) or beverages (like wine) that contain them.
Be alert for warning signs of an asthma attack.
- Watch for symptoms (for example, coughing,
wheezing, chest tightness, and difficulty breathing) and use your quick-relief
medicine as directed by your doctor.
- Use your peak flow meter as directed to monitor
your asthma.
If your asthma is not under control, there will be
signs that you should not ignore. The following are some signs that your asthma
is getting worse:
- You have asthma symptoms more often than usual.
- Your asthma symptoms are worse than they used to
be.
- Your asthma symptoms are bothering you a lot at
night and making you lose sleep.
- You are missing school or work because of your
asthma.
- Your peak flow number is low or varies a lot from
day to day.
- Your asthma medicines do not seem to be working
very well anymore.
- You have to use your short-acting quick-relief,
or "rescue," inhaler more often. (Using quick-relief medicine every day or
using more than one inhaler a month is too much.)
- You have to go to the emergency room or doctor
because of an asthma attack. You end up in the hospital because of your asthma.
If your asthma seems to be getting worse, see your
doctor. You may need to change your medicines or do other things to get your
asthma under control.
Helping Your Child Live With Asthma
Children with asthma need the help of parents, other
caregivers, teachers, and health care professionals to keep their asthma under
control.
You can help your child with asthma keep it under
control. For example, you can:
- Take your child to the doctor for regular
checkups and treatment.
- Make sure your child has an asthma
self-management plan and that you know how to follow it.
- Help your child learn about asthma and how to
control it.
- Help your child learn what things cause his or
her asthma symptoms and how to avoid them, if possible.
- Protect your child from tobacco smoke by not
smoking and not allowing people to smoke in your home.
- Find ways to reduce your child's exposure to
allergens that bring on asthma attacks, like pollen, dust mites, cockroaches,
or animal dander.
- Make sure your child knows how to take asthma
medicines correctly (if your child is old enough to use an inhaler without your
help).
- Make sure that your child uses a peak flow meter
to help monitor and control asthma.
- Encourage your child to take part in physical
activity. Work together to keep his or her asthma under control. Your child can
be active.
- Talk to your child's other caregivers, teachers,
or coaches about his or her asthma; give them copies of your child's asthma
self-management plan.
Key Points
- Asthma is a chronic disease that affects your
airways, the tubes that carry air in and out of your lungs.
- In asthma, the inside walls of your airways are
inflamed, or swollen. The inflammation makes them very sensitive, and they tend
to react strongly to things that you are allergic to or find irritating. When
they react, they get narrower and less air flows through to your lungs. This
causes symptoms like wheezing, coughing, chest tightness, and trouble
breathing, especially at night and in the early morning.
- Asthma cannot be cured, but most people with
asthma can control it so that they have few and infrequent symptoms and can
live normal, active lives.
- When your asthma symptoms become worse than
usual, it is called an asthma episode or attack. In a severe asthma attack, the
airways can close so much that not enough oxygen can get to your vital organs.
People can die from severe asthma attacks.
- Taking care of your asthma is an important part
of your life. Controlling it means working closely with your doctor to learn
how to manage your condition, staying away from things that bother your airways
and bring on asthma symptoms, taking medicines as directed by your doctor, and
monitoring your asthma so you can respond quickly to signs of an attack. Ask
your doctor for a written daily asthma self-management plan and an emergency
action plan for asthma attacks, and make sure you understand and know how to
use them.
- Researchers still do not know what causes asthma,
although they do know that if other people in your family have asthma, you are
more likely to develop it. Being exposed early in your life to things like
tobacco smoke, infections, and some allergens may also increase your chances of
developing asthma.
- Some of the more common things that bring on
asthma symptoms include exercise, allergens, irritants, and viral infections.
- Common asthma symptoms include coughing,
wheezing, chest tightness, shortness of breath, and faster or noisy breathing.
- Doctors find out whether you have asthma by
looking at your family history of asthma and allergies, exploring the things
that seem to cause your symptoms or make them worse, and giving you a test,
called spirometry, that measures how much air you can blow out of your lungs
after taking a deep breath and how quickly you can do it. They may also perform
tests to find out if you have allergies, to see how your airways react to
exercise, to find out whether you have gastroesophageal reflux disease or sinus
disease, and to rule out heart disease and other lung diseases.
- Asthma is treated with two kinds of medicines:
quick-relief medicines to stop asthma symptoms and long-term control medicines
to prevent symptoms.
- Short-acting inhaled beta-agonists are the
preferred quick-relief medicine. The most effective, long-term control medicine
is an inhaled corticosteroid, which reduces inflammation in your lungs. Most
long-term control medicines must be taken daily, even when you do not have
symptoms.
- Other long-term control medicines include inhaled
long-acting beta-agonists, leukotriene modifiers, cromolyn, and theophylline.
- Most asthma medicines are inhaled. As a result,
they go straight to your lungs where they are needed. It is important to learn
how to use your inhalers correctly.
- Many people with asthma need to monitor their
condition with a peak flow meter. This is a hand-held device that measures how
well your lungs are working. A peak flow meter can help you detect early
changes in your condition, especially if you change your medicines, and warn
you of a possible attack even before you feel symptoms.
- Parents of children with asthma need to help them
manage their asthma, including making sure the child uses his or her medicines
properly and watching for any signs of an attack.
- Older people with asthma may need to adjust their
treatment because of other diseases or conditions that they have. Some
medicines that many older people take can interfere with asthma medicines or
even cause asthma attacks.
- It is especially important for pregnant women
with asthma to control their asthma. Uncontrolled asthma can limit the supply
of oxygen to the fetus. Doctors recommend that it is safer to take asthma
medicines during pregnancy than to take the chance that you will have an
attack.
- Regular physical activity is just as important
for people with asthma as for the rest of the population. If exercise brings on
your asthma symptoms, talk to your doctor about the best ways to control your
asthma when you are active.
Links to Other Information About Asthma
NHLBI Resources
Non-NHLBI Resources
Clinical Trials
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