An allergy is the immune system’s excessive sensitivity and overresponse to a harmless foreign substance in the body. Allergens are found in indoor and outdoor environments and may come from a variety of sources. Common allergens include pollen, mold, animal dander, dust mites, and food components.
What’s the difference between an allergy and a cold?
Though allergies and colds often have similar symptoms, they are very different. A cold is a virus while an allergy is caused by a hypersensitive immune system attacking an allergen. Here’s a breakdown of the two: