Allergy

What are allergies?

When most people think of an allergy, they think of the sneezing, congestion, and itchy eyes caused by pollen. In fact, allergies can be caused by just about any substance that you inhale or swallow, or which touches your skin.

An allergy is an overreaction of the immune system to a substance that's harmless to most people. But in someone with an allergy, the body's immune system treats the substance (called an allergen) as an invader and reacts inappropriately, resulting in symptoms that can be anywhere from annoying to possibly harmful to the person.

Who Gets Allergies?

allergic diseases can arise at any age, they generally begin in childhood.

Why are allergic reactions on the rise in Western industrialized countries? There are several theories, but many experts view the increase in allergies as the price of success.

Common Airborne Allergens

Some of the most common things people are allergic to are airborne (carried through the air):

Dust mites

Pollen

Pet allergens