You have an allergy when your body overreacts to things that don’t cause problems for most people. These things are called allergens. Your body’s overreaction to the allergens is what causes symptoms (see the box below for a list of symptoms). For example, sometimes the term “hay fever” is used to describe your body’s allergic reaction to allergens in the air.


Your doctor may want to do an allergy skin test to help determine exactly what is causing your allergy. An allergy skin test puts tiny amounts of allergens onto your skin to see which ones you react to. Once you know which allergens you are allergic to, you and your doctor can decide the best treatment. Your doctor may also decide to do a blood test, such as the radioallergosorbent test (called RAST) or the ELISA test.