What is AED? | Learn What an AED Is - American Red Cross

08 Sep.,2025

 

What is AED? | Learn What an AED Is - American Red Cross

If you're wondering what an AED is – and why they seem to be located in most offices and public buildings, you're not alone. In fact, because these devices are now commonly available, more people than ever before are curious about them. So – just what is an AED?

Click here to get more.

What Does AED Stand for?

AED stands for automated external defibrillator.

What is an AED Used for?

AEDs are used to help those experiencing sudden cardiac arrest. It's a sophisticated, yet easy-to-use, medical device that can analyze the heart's rhythm and, if necessary, deliver an electrical shock, or defibrillation, to help the heart re-establish an effective rhythm.

The device is designed to be user-friendly, with clear instructions on how to use it in case of an emergency. It's important for everyone to be aware of what an AED is and how to use it, as it could make a difference in saving someone's life.

AED - Step by Step

Courses through the Red Cross will train you on the proper AED steps, so you can ensure you’re using an AED the right way. To refresh your skills after becoming AED certified, you can come back and review this 7 steps of using an AED guide.

Why Learn to Use an AED

Sudden cardiac arrest is among the leading causes of death in the United States. In fact, more than 350,000 people will suffer a cardiac arrest this year. Currently, the only way to restore a regular heart rhythm during cardiac arrest is to use an AED.

Of course, you can – and should – request the assistance of trained medical professionals. However, because the average response time for first responders once 911 is called is 8-12 minutes, and for each minute defibrillation is delayed, the odds of survival are reduced by approximately 10%, having access to and AED and knowing how to use one, is critical.

CPR/AED Classes

At the Red Cross, you can choose the type of class for your schedule – and the way you learn best. For those who want to become certified in CPR/AED, you can choose from three types of courses, including:

  • In Person: Designed for those who learn best in a traditional classroom setting, our in-person courses combine lecture with hands-on skills sessions. This way, you can not only learn what an AED is, what it looks like, how to it, but you can demonstrate your skills to a certified instructor. If the course is completed with a passing grade, you'll receive a two-year certification.
  • Online: Perfect for those who want the freedom to take self-paced courses, our online classes can help you learn AED best practices. However, online safety training courses do not allow you to demonstrate your skill proficiency to a certified instructor, and therefore your certification may not meet the requirements for workplace safety.
  • Blended Learning: Featuring award-winning simulation learning, our blended learning programs combine self-paced, interactive instruction and in-person skills sessions. That way, you can learn what an AED is – and how to use one – in theory and in practice. Additionally, because this option allows you to demonstrate your skills to a certified instructor, you can receive full certification with a passing score.

AED Course Topics

Typical topics covered in Red Cross AED classes include:

  • Recognizing Emergencies and Gaining Confidence to Act
  • Emergency Action Steps
  • Recognizing Cardiac Arrest
  • Giving CPR
  • Safe and Effective Use of AEDs

We have courses geared towards CPR and AED use for infants, children, and adults. In our Adult Child and Baby First Aid/CPR/AED course, additional topics may include:

  • AED use for adults and children
  • Signs of pediatric cardiac arrest
  • How to use AEDs in children and infants safely

Where to Buy an AED

Having an AED on site can make a significant difference in emergencies and could potentially save lives. Cardiac arrest can happen to anyone, anywhere, at any time, which is why having AEDs readily available in public places is so important. If you are looking to purchase an AED for your workplace, the Red Cross offers exclusive deals. Learn more about our total AED purchasing and training solution or contact us to acquire this life-saving device for your business.

Why Train With the Red Cross


When To and When Not to Use an AED

Knowing when not to use a defibrillator is just as important as knowing how to use an AED, and where to find one. Here’s why.

Automated External Defibrillators (AEDs) save over 1,700 lives in the United States every year. However, many Americans do not currently know where to locate AEDs or how to use them. At Avive, we see room for improvement to save thousands more lives annually. 

AEDs are medical devices that send electric pulses to a person's heart, restoring a normal heart beat. AEDs are the only way to restore a normal heartbeat when someone is experiencing Sudden Cardiac Arrest (SCA).

Knowing where to find and how to use an AED is vitally important. But some patients with irregular heartbeats, or in certain circumstances, should never be treated with an AED. Knowing when to use an AED and when not to use one is an equally essential skill in saving a life.

When to Use an AED (Defibrillator)

You should only use an AED on a person if:

  • their heart suddenly stops beating
  • they are experiencing Sudden Cardiac Arrest (SCA). Symptoms are immediate and drastic and include:
  • No breathing, or gasping noises paired with abnormal breathing
  • Unresponsive
  • Unconscious
  • No pulse

If you encounter someone with these symptoms, call 911, designate someone to search for a defibrillator, and immediately begin CPR.  It is important to acknowledge that over 80% of SCAs cases occur in the home, which underscores the importance of having an emergency action plan in place.

When NOT to Use an AED (Defibrillator)

There are various special circumstances that require extra care when determining if and how to use an AED. All AED units have their own intended use statements, so we recommend all AED owners review their unit's requirements.

The Victim Is Conscious & Breathing Normally

If the person is conscious and breathing normally, they do not require an AED shock. 

Generally speaking, an AED should be used when a person is unconscious (not responsive) and not breathing properly. It is important to know that sometimes victims of Sudden Cardiac Arrest in this state may demonstrate agonal breathing for seconds to minutes after their heart has stopped beating. Agonal breathing is NOT normal breathing. It is crucial that you do not mistake agonal breathing for real breathing. Agonal respirations can sound like gasping, snorting, strange, shallow half-breaths, or possibly moaning. A person experiencing agonal breathing may also show signs of twitching muscles. When a person is not responsive and breathing agonally, an AED should be used.

The Victim Has a DNR

If you notice a bracelet or a tattoo on the victim’s chest, wrist or forearm saying, “Do Not Resuscitate” or “DNR”, do not use an AED on them. The DNR order indicates that the person does not want resuscitation. It is best that you respect their wishes.

Jousing Medical supply professional and honest service.

Faulty AED Parts

If your AED has faulty parts it may not be functional. If you're stuck with a non-functional AED during an emergency, search for another one nearby.

When Special AED Use Circumstances Might Apply

The Patient Has a Pacemaker or Medication Patch

While pacemakers are designed to handle shocks from an AED, you should not  use a defibrillator over the skin where surgeons installed the pacemaker.

A pacemaker can usually be seen or palpated under the skin, in the upper part of the person's chest. Ensure you follow any instructions for responding to victims with a pacemaker found in your AED’s user manual and place the AED pads where indicated.

Do not place AED pads over medical patches. Remove them first.

The Person Is Wet or Lying on a Wet Surface

SCA can happen at any time, including when a person is in or near a body of water, or in the rain or snow. In wet conditions, AEDs can be dangerous to use, causing harm to the victim or the person providing the care. Since AEDs deliver an electrical shock, you must take specific care when treating the cardiac arrest victim.

Never use an AED while submerged in water. Always move someone submerged in water to dry land before delivering an AED shock. You cannot apply the AED pads, which deliver the necessary electrical shock to the victim’s chest, until the shirt has been removed and the skin dried thoroughly. Once the person’s skin is dry, power on the AED and follow its instructions the same way you would during a normal response.

The Victim Has a Hairy Chest

AED pads need direct contact with the patient’s skin in order to work properly. If the person has a very hairy chest, it may be necessary to remove some hair so the electrode pads will adhere properly to the person’s skin. Many defibrillator kits include a razor to quickly shave the victim’s chest. If you cannot find a razor, apply pressure to place the pads as close to their chest as you can.

The Person Is Suffering From Heart Attack

The main difference between Sudden Cardiac Arrest and heart attack is the underlying problem that occurs in the heart. 

  • Cardiac arrest is an electrical problem where a malfunction in the heart’s electrical system causes it to stop beating. Normally, the heart is controlled by regular electrical impulses that make it beat. When Sudden Cardiac Arrest happens, these electrical impulses become scrambled and the heart can no longer pump blood (containing oxygen that is necessary for life) around the body. 
  • By contrast, a heart attack is when the blood supply to the heart is cut off due to a blockage in an artery. This blockage causes damage to the heart and the muscle begins to die. 

If the patient is having a heart attack they will be breathing and conscious, in these cases an AED is not needed to restart the heart. Victims of cardiac arrest, however, will suddenly become unconscious and collapse. They will be unresponsive and not breathing or breathing agonally (abnormally). Unlike cardiac arrest, which always happens suddenly, a heart attack can be sudden or may develop over time. 

Learn more about the signs and symptoms of a heart attack.

If someone is experiencing a heart attack, immediately call 911.

Safety Considerations for AED Users - Using an AED on Infants and Children

AED pads come in multiple sizes, infant and adult. Ensure you use the appropriate pads for the size (age or weight) of the victim. Your AED’s user manual will disclose when to use adult pads and when to use child pads, as well as any other special circumstances that might exist.

Learn more about how to resuscitate infants and children.

When using an AED on someone suffering from SCA, keep the following in mind:

  • Avoid areas with a buildup of flammable vapors. Sparks from the AED could cause a fire.
  • Do not touch the patient with any part of your body while the AED is delivering a shock. Clear the area around the victim and prevent anyone else from touching the patient. 
  • Do not use an AED while riding in a moving vehicle.

Always check your AED manufacturer’s user manual for specific safety and operational and maintenance instructions pertaining to your AED unit.

Time is of the Essence

During cardiac arrest, a person's chances of survival drop by 10% per minute, so it is critical that you quickly decide when to use an AED and determine where it is located.

Here are a few critical questions that you must ask yourself in order to make a quick decision:

  • Is the AED operational?
  • Does the situation call for the use of an AED?
  • Does the person suffering from Sudden Cardiac Arrest require any special care (such as having a pacemaker, being a young child or infant, or having a hairy chest)?
  • Does the scenario have any special circumstances (such as a wet or unsafe location, or faulty AED parts)?

*All information on the Avive website is provided in good faith. However, Avive makes no representation or warranty of any kind, express or implied, regarding the accuracy, validity, or completeness of any information on the Site. Any medical/health information on the Site is for general informational and educational purposes only and is not a substitute for professional medical/health advice.

UNDER NO CIRCUMSTANCE SHALL WE HAVE ANY LIABILITY TO YOU FOR ANY LOSS OR DAMAGE OF ANY KIND INCURRED AS A RESULT OF THE USE OF THE SITE OR INFORMATION PROVIDED ON THE SITE. YOUR USE OF THE SITE AND YOUR RELIANCE ON ANY INFORMATION ON THE SITE IS SOLELY AT YOUR OWN RISK.

For more aed defibrillator portableinformation, please contact us. We will provide professional answers.