What Happens
Asthma often begins during infancy or childhood but
may start at any age and last throughout your life. It can increase your risk
for complications from lung and airway infections, such as acute
bronchitis and
pneumonia.
At times, the
inflammation
from asthma causes a narrowing of your
airways and
mucus production, resulting in asthma symptoms such as
shortness of breath.
The airways narrow when they overreact to certain substances. These
are known as asthma
triggers and may include:
- Substances you are allergic to (allergens, such as
dust mites or
animal dander). Allergens cause long-term (chronic)
inflammation and may cause asthma symptoms.
- Environmental
factors, such as smoke or cold air. Environmental factors may lead to a
tightening of the muscles that line the bronchial tubes (bronchospasm), which can trigger asthma
symptoms.
What triggers asthma symptoms varies from person to person. When
asthma is triggered by an allergen, it is called
allergic asthma.
When asthma symptoms suddenly occur, it is called an
asthma attack (also called a flare-up or
exacerbation). Asthma attacks can occur rarely or frequently and may be mild to
severe. Although some asthma attacks occur very suddenly, many become worse
gradually over a period of several days. Generally, you can take care of
symptoms at home with an
asthma action plan, although a severe attack may
require emergency treatment and on rare occasions can be fatal.
Asthma is
classified as mild intermittent, mild persistent,
moderate persistent, and severe persistent.
- People with mild intermittent asthma often have
symptoms only after being around a trigger.
- People with mild
intermittent asthma usually need medications only during an asthma
attack.
- People with mild persistent or moderate persistent asthma
may not always have noticeable symptoms, but they need to take medications
daily to control the long-term inflammation in their
airways.
- People with severe persistent asthma have symptoms almost
all of the time. Their symptoms need to be treated daily. These people are at
increased risk for severe, life-threatening asthma attacks known as
status asthmaticus.
Asthma—even mild asthma—may result in changes to the airway system
(airway remodelling) and may speed up and make worse the natural decrease in
lung function that occurs as we age.3 Asthma may raise
your risk for developing
chronic obstructive pulmonary disease (COPD).4
Sometimes asthma does not respond to treatment because people are
not taking their medications, not taking them correctly, not avoiding triggers,
or otherwise not following their
daily
treatment plans or asthma action plans. Follow your asthma plans so you
can prevent worsening asthma and an
increased risk of death.
Asthma during pregnancy
Asthma can affect your pregnancy. It may occur for the first time
during pregnancy, or it may change during pregnancy.
When asthma is properly controlled, a pregnant woman with asthma
can have a normal pregnancy with little or no increased risk to herself or her
fetus. But if the asthma is not well controlled, there
are risks to the pregnant woman and her fetus. The management of
asthma in pregnant women and non-pregnant women is
basically the same, although a pregnant woman may need to take different
medications and needs to monitor the fetus's health as well as her own.