Health Topics

Overview of Asthma and Allergies

Overview of Asthma and Allergies

What is asthma?

Asthma is a disorder of the lungs that causes the airways to:

  • Swell (or become inflamed), specifically in the airway linings
  • Produce large amounts of mucus that is thicker than normal
  • Become more narrow due to muscle contractions surrounding the airways

The symptoms of asthma are:

  • Feeling short of breath
  • Frequent coughing, especially at night
  • Wheezing (a whistling noise during breathing)
  • Difficulty breathing

Asthma is very common; it affects about 5 to 10 percent of children in the United States and is the most common chronic condition of childhood. Uncontrolled asthma in children can lead to missed school days, interrupted sleep patterns and, ultimately, poor school performance. It is important to realize, however, that asthma symptoms can begin at any age from infancy through adulthood.

What causes asthma?

The cause of asthma is uncertain. Among those at higher risk for asthma are those who:

  • Have a family history of asthma
  • Have a history of allergies
  • Have smokers living in the household
  • Live in urban areas

What are allergies?

Allergies are the body’s incorrect response to a foreign substance. Exposure to what is normally a harmless substance (such as plant pollen, mold, or animal hair) causes the immune system to react as if the substance is harmful. Substances that cause allergies are called "allergens." Another term for allergy is “immediate hypersensitivity,” because of the way an allergic reaction takes place.

Allergies cause:

  • Inflammation (swelling) of the hypersensitive area
  • Occasional inflammation of non-exposed areas (anaphylaxis)
  • A variety of respiratory complaints such as cough, increased mucous production, and sneezing
  • Increased risk of chronic respiratory infections such as sinusitis

What has been the effect of asthma and allergies on society?

  • Approximately 20 million Americans have asthma, including 9.1 million children
  • 4 million children suffered an asthma attack in the past 12 months (2003)
  • 12.8 million school days are missed annually due to asthma
  • 24.5 million work days are missed annually by adults due to asthma
  • Approximately 5,000 deaths occur annually from asthma
  • Total costs for treatment of asthma in the US are $16.1 billion annually [direct costs total $11.5 billion and indirect costs (e.g., lost productivity) total an additional $4.6 billion]
  • 10 million Americans have allergic asthma; this represents 70% of all asthmatics in the US
  • Allergies affect 40 to 50 million Americans
  • Allergies are the sixth leading cause of chronic disease in Americans
  • Approximately 35.9 million Americans have hay fever (seasonal allergic rhinitis)
  • Total costs of allergies were estimated to be $6 billion in 1996
  • Skin allergies (e.g., dermatitis) occur in an estimated 10 percent of American children
  • 40 deaths per year occur as a result of anaphylaxis due to insect stings

What can be done?

In most cases, your physician can effectively manage asthma and allergies and will:

  • Identify and reduce your exposure to known triggers (substances that produce asthma symptoms)
  • Offer an individualized disease management plan that includes measurement of disease severity, provision of medications, and means to seek medical attention and information
  • Consult with pediatric asthma and allergy specialists when needed