What causes allergies

What Is an Allergy?

An allergy is technically defined as an overreaction by the body's immune system to a normally harmless substance. It's kind of like people who just completely freak out at the sight of a mouse or bug that's more afraid of the person screaming than the other way around.

Your immune system contains a collection of molecules and cells that release substances to fight off disease. But sometimes, this arsenal of weapons and soldiers is unleashed on completely harmless things. The substances that trigger an allergic reaction are called allergens and include environmental allergens, such as:

- Dust mites
- Pollen
- Mold
- Pet dander

One problem caused by allergies is allergic rhinitis. Allergic rhinitis is an allergen-induced inflammation of the nasal membranes that results in your stereotypical congestion, itching, and sneezing.