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What Is an AED (Automated External Defibrillator)?

Medically reviewed by: Amy W. Anzilotti, MD

What Is an AED?

An AED (automatic external defibrillator) is a medical device used to treat cardiac arrest. In cardiac arrest, changes in the heart's normal electrical activity make it suddenly stop beating.

What Does an AED Do?

When a person is in cardiac arrest, an AED checks their heart’s electrical activity and tells the AED user whether to give the person an electric shock. The shock can sometimes get the heart back into a normal rhythm.

Where Are AEDs?

AEDs are kept in many public places, including schools and sports facilities. They are made to be easy for bystanders to use because quick medical care makes a person more likely to survive cardiac arrest.

What Else Should I Know?

Consider getting trained to use an AED. Older kids and teens can learn this too. Many AED classes also include CPR training because people in cardiac arrest often need CPR too. By being ready, you may save someone’s life.

Medically reviewed by: Amy W. Anzilotti, MD
Date reviewed: January 2023