What Causes Allergies?

Medically Reviewed by Carmelita Swiner, MD on September 01, 2022

Almost anything can trigger allergies. Common culprits include:

Minor injuries, extreme temperatures, exercise, or even emotions can trigger your symptoms, even though you may not have been allergic to these things.

While there are common allergens, your particular triggers are unique to you. They can even change over time. For instance, your body may develop a poison ivy allergy from repeated exposure.

Allergies run in some families. But you can have them even if your parents don’t. Many people who get symptoms from one thing react to other things, too.

You’re more likely to have allergies if you’ve had:

Show Sources


William Larry Haith, DO, FAAEM, consulting staff, Department of Emergency Medicine, Southern Maine Medical Center.

National Institute of Allergy and Infectious Diseases.

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