What is asthma?
Asthma is a chronic disease that affects the
airways of the lungs. During normal breathing, the bands of muscle that
surround the airways are relaxed and air moves freely. During an asthma
episode or "attack," there are three main changes that stop air from
moving easily through the airways:
- The bands of muscle that surround the airways tighten and make the airways narrow. This tightening is called bronchospasm.
- The lining of the airways becomes swollen or inflamed.
- The cells that line the airways produce more mucus, which is thicker than normal.
These three factors - bronchospasm,
inflammation, and mucus production - cause symptoms such as difficulty
breathing, wheezing, and coughing.
What are the most common symptoms of asthma?
Asthma symptoms are not the same for everyone. They can even change from episode to episode in the same person.
Also, you may have only one symptom of asthma, such as cough, but another person may have all the symptoms of asthma. It is important to
know all the symptoms of asthma and to be aware that your asthma can present in any of these ways at any time.
The most common symptoms include:
- Coughing, especially at night
- Shortness of breath
- Wheezing
- Chest tightness, pain, or pressure
Who is affected by asthma?
Asthma affects 22 million Americans; about 6
million of these are children under age 18. People who have a family
history of asthma have an increased risk of developing the disease.
Asthma is also more common in people who have allergies or who are
exposed to tobacco smoke. However, anyone can develop asthma at any
time. Some people may have asthma all of their lives, while others may
develop it as adults.
What causes asthma?
The airways in a person with asthma are very
sensitive and react to many things, or "triggers." Contact with these
triggers causes asthma symptoms. One of the most important parts of
asthma control is to identify your triggers and then avoid them when
possible. The only trigger you do not want to avoid is exercise.
Pre-treatment with medicines before exercise can allow you to stay
active yet avoid asthma symptoms.
Common asthma triggers include:
- Infections (colds, viruses, flu, sinus infections)
- Exercise
- Weather (changes in temperature and/or humidity, cold air)
- Tobacco smoke
- Allergens (dust mites, pollens, pets, mold spores, cockroaches, and sometimes foods)
- Irritants (strong odors from cleaning products, perfume, wood smoke, air pollution)
- Strong emotions such as crying or laughing hard
- Some medications