An allergy is a specific reaction of the body’s immune system to a normally harmless substance, one that does not bother most people. Health experts estimate that 35 million Americans suffer from upper respiratory tract symptoms that are allergic reactions to airborne allergens.

People who have allergies often are sensitive to more than one substance. Common types of airborne allergens that cause allergic reactions include:

Pollen allergy, commonly called hay fever, is one of the most common chronic diseases in the United States. Worldwide, airborne allergens cause the most problems for people with allergies. The respiratory symptoms of asthma, which affect approximately 11 million Americans, are often provoked by airborne allergens.

The American Lung Association Health House^® has practical information on how you can reduce your exposure to common airborne allergens.