An allergy test is an exam performed by a trained allergy specialist to determine if your body has an allergic reaction to a known substance. The exam can be in the form of a blood test, a skin test, or an elimination diet.

Allergies occur when your immune system, which is your body’s natural defense, overreacts to something in your environment. For example, pollen, which is normally harmless, can cause your body to overreact. This overreaction can lead to:

• a runny nose
• sneezing
• blocked sinuses
• itchy, watery eyes