Asthma in Teens and Adults - Cause
The cause of
asthma is not known. Health experts believe that
inherited, environmental, and
immune system factors combine to cause
inflammation of the bronchial tubes, which carry air
to the lungs. This can lead to asthma and
- Asthma may run in families (be inherited). If
this is the case in your family, you may be more likely than other people to
develop long-lasting (chronic) inflammation in the bronchial tubes.
- In some people,
immune system cells release chemicals that cause
inflammation in response to certain substances (allergens) that
allergic reactions. Studies show that exposure to
allergens such as
dust mites, cockroaches, and
animal dander may influence asthma?s
development.1 Asthma is much more common in people
with allergies, although not all those who have allergies develop asthma. And not
all people with asthma have allergies.
- Environmental factors and
today's germ-conscious lifestyle may play a role in the development of asthma.
Some experts believe that there are more cases of asthma because of pollution
and less exposure to certain types of bacteria or infections.2 As a result, children's immune systems may develop in a way
that makes it more likely they will also develop allergies and asthma.
Asthma in adults also can be related to work (occupational asthma). Being around animals, plastic
resin, wood dust, grain dust, insecticides, and metals can cause asthma,
usually because your
immune system reacts to the material. Some people
continue to have asthma symptoms even after they are no longer exposed to what
caused the symptoms. But for many people, symptoms will get better or go away
when they are away from the