Allergies Health Center
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Blocking Allergy Symptoms: How Pretreatment Works
Tackle allergies before they start -- and you could be breathing a lot easier.
Tackle allergies before they start -- and you could be breathing a lot easier.
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Allergy Basics
What Are Allergies?
Allergies are an abnormal response of the immune system. People who have allergies have an immune system that reacts to a usually harmless substance in the environment. This substance (pollen, mold, animal dander, etc.) is called an allergen.
Allergies are a very common problem, affecting at least 2 out of every 10 Americans.



