Asthma, Part 1 — Introduction, incidence, and symptoms
What is Asthma?
Asthma is a chronic condition which involves the lungs. When an individual has asthma,
the passages from the lungs to the nose and mouth (the airways) are overly sensitive
and become narrow, causing difficulty in breathing. Asthma is an excessive response
to “triggers” such as dust or other irritants in the air that cause changes in the
airways.
There are certain things that commonly cause these changes to occur. Those
include weather conditions, allergens in the environment (such as cat, dog, guinea
pig dander, cigarette smoke, mold, dust, etc.), food allergies or respiratory infections
(colds). When a reaction to these triggers occurs, it is called an “asthma attack”.
An asthma attack consists of swelling and inflammation of the airways.
In addition,
there is a reversible tightening of the tiny muscles that surround the airways.
This tightening is called bronchospasm (BRONK-oh-spa-zem). Medications are used to prevent and reverse
an asthma attack. In very severe cases of asthma, permanent narrowing of the airways
can occur, as a result of damage to the lungs.
An individual with asthma does not have trouble with breathing all the time. As
a matter of fact, they can usually breathe normally. However, when a trigger is
present in their environment, an asthma attack may result very quickly. Triggers
are not the same for all persons with asthma. Some people have reactions to several
different triggers, while others may react to only a certain trigger. Indoor triggers
(aerosol sprays, dust, etc.) can be just as problematic as outdoor triggers.
Common
triggers include:
- Tobacco smoke
- Dust
- Mold
- Pollen
- Exercise
- Viral infections, colds
- Animal hair or dander
- Chemicals (airborne or in food)
- Weather changes (especially sudden cold)
- Strong emotional responses
- Aspirin or other medications
Children are particularly vulnerable to asthma attacks, as their airways are narrower
than those of adults. Due to this, triggers that may cause only a slight response
in adults may cause a severe response in a child.
Asthma attacks may have a sudden
onset and be very severe in children. Thus, it is very important that the diagnosis
be made and that asthma be treated correctly in children. This may require that
a child take asthma medications even at times when she is not having difficulty
with breathing. Preventing an asthma attack is preferable to treating a serious one.
Incidence/prevalence
Approximately 17.3 million Americans have asthma. The prevalence of asthma in the
general population is 5%, and it has increased 40% in the past decade. Asthma accounts
for more school absences than any other chronic illness. Asthma accounts for more
hospitalizations in children than any other chronic illness. In most children's
hospitals in the United States, it is the most common diagnosis at admission.
Despite
advancements in our understanding of asthma and the development of new therapeutic
strategies, the morbidity and mortality rates due to asthma definitely increased
between 1980-1995. In the United States, the mortality rate due to asthma has increased
in all age, race, and gender groups. In the United States, the mortality rate due to
asthma is more than 17 deaths per 1 million population (ie, 5000 deaths per year).
From 1975-1993, the number of deaths nearly doubled in people aged 5-14 years.
The
incidence of asthma is higher in minority groups (eg, blacks, Hispanics) than in
other groups. However, findings from one study suggest that much of the recent increase
in the incidence is attributed to asthma in white children. About 5-8% of all black
children have asthma at some time. The incidence in Hispanic children is reported
to be as high as 15%. In blacks, the death rate is consistently higher than in whites.
Before puberty, the incidence is 3 times higher in boys than girls. The incidence
is equal among males and females during adolescence. Adult-onset asthma is more
common in women than in men. In most children, asthma develops before they are aged
5 years, and, in more than half, asthma develops before they are aged 3 years.
There
has been a worldwide increase in the incidence of asthma in children in recent years.
This is thought to be linked to environmental factors, including air pollution.
Asthma, Part 1 — Introduction, incidence, and symptoms
For more information, please contact:
Kathy Davis, MSEd, PhD
kdavis2@kumc.edu
(913) 588-6305