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 and clogs the airways.

These three factors - bronchospasm, inflammation, and mucus production - cause symptoms such as difficulty breathing, wheezing, and coughing.

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

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

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