An AED is the public-access defibrillator that gives spoken instructions and may deliver a shock during cardiac arrest.
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Quick answer
AED: A means Automated; E means External; D means Defibrillator. An AED is the public-access defibrillator that gives spoken instructions and may deliver a shock during cardiac arrest.
When AED helps
Use an AED on someone who is unresponsive and not breathing normally. Turn it on, call Triple Zero (000) and ask for an ambulance, expose and dry the chest if needed, attach pads, keep CPR going when the AED allows, and make sure no one touches the person during rhythm checks or shock delivery.
Safety boundary: A remembered sequence must never delay CPR, defibrillation or a Triple Zero (000) call. If a real incident is unfolding, act on the person’s condition, call Triple Zero (000) when it is an emergency and follow the operator’s instructions.
Where it sits: AED is commonly read alongside PAD, OHCA, VF, ALS, but each term has a different job. The comparisons later on this page explain those boundaries.
What Does AED Stand For?
| A | Automated The device analyses the heart rhythm and tells rescuers what to do. |
| E | External Pads are placed on the outside of the chest. |
| D | Defibrillator The device may advise and deliver a shock if it detects a shockable rhythm. |
Common Mistakes
- Do not wait for a trained person before turning on the AED.
- Do not remove the pads once attached unless emergency services tell you to.
- Do not touch the person while the AED is analysing or shocking.
AED Step-By-Step For Beginners
Use this detailed sequence when learning how AED applies to defibrillation, cardiac arrest and public rescue. It connects the letters to observable checks, clear words and a useful handover rather than treating the acronym as a bare list.
- Confirm the emergency. An AED is for a person who is unresponsive and not breathing normally. Start CPR first.
- Turn it on. Open the lid or press the power button. The AED will talk you through each step.
- Call Triple Zero (000) and ask for an ambulance. If not already done, call Triple Zero (000) and ask for an ambulance. Put the phone on speaker so you can keep working.
- Attach pads quickly. Expose the chest, wipe/dry if needed, and apply pads as shown on the pictures. Keep pauses short: keep CPR going and only stop when the AED tells you to.
- Stand clear for analysis/shock. Make sure nobody is touching the person when the AED says it is analysing or delivering a shock.
- Resume CPR. After a shock or a ‘no shock’ message, go straight back to CPR until the AED tells you to pause again.
A Real-World AED Scenario
The scene: At a club, one person continues CPR while another returns with an AED. Turn it on and follow the voice prompts.
Make sure no one touches the person while the AED analyses or gives a shock. Resume CPR when the device prompts you to.
Where the scenario could change: Do not wait for a trained person before turning on the AED. A remembered sequence must never delay CPR, defibrillation or a Triple Zero (000) call. If the facts no longer fit a stable AED example, stop rehearsing the acronym and move to the safer emergency, clinical or workplace pathway.
AED and similar terms
An automated external defibrillator: a device that checks the heart rhythm and gives spoken instructions. CPR is the hands-on care; the AED is the device used alongside it.
Here is how the related terms differ:
- PAD: Public access defibrillation: making AEDs available in places such as workplaces and sports grounds. It describes access to equipment.
- OHCA: Out-of-hospital cardiac arrest. It names where the cardiac arrest happened, rather than a different kind of CPR.
- VF: Ventricular fibrillation: a dangerous heart rhythm that can cause cardiac arrest. An AED checks the rhythm; a first aider does not need to identify VF themselves.
- ALS: Advanced life support, provided by appropriately trained health professionals using additional treatments and equipment.
Frequently asked questions
What does AED stand for?
A means Automated; E means External; D means Defibrillator. An AED is the public-access defibrillator that gives spoken instructions and may deliver a shock during cardiac arrest.
When is AED useful?
Use an AED on someone who is unresponsive and not breathing normally. Turn it on, call Triple Zero (000) and ask for an ambulance, expose and dry the chest if needed, attach pads, keep CPR going when the AED allows, and make sure no one touches the person during rhythm checks or shock delivery.
Do I need training to use an AED?
No formal training is required. AEDs are designed for bystanders: turn it on, follow the prompts, and call Triple Zero (000) if not already done.
Can an AED shock someone who does not need it?
AEDs analyse the rhythm and will only advise a shock for certain rhythms, but you should still only use an AED for someone who is unresponsive and not breathing normally, and follow prompts exactly.
Do I remove clothing first?
Expose enough of the chest so pads can stick (cut or tear clothing if needed). Keep pauses short: keep CPR going and follow the AED prompts.
How is AED different from PAD?
AED is framed here around defibrillation, cardiac arrest and public rescue. PAD is framed around AED programs, community defibrillators, workplaces, clubs, schools and public spaces. They may appear in the same course or incident, but they answer different questions and should not be treated as interchangeable.
When should I call Triple Zero (000)?
Call Triple Zero (000) when the person is seriously ill or injured, is deteriorating, or the urgent warning signs described on this page are present. A remembered sequence must never delay CPR, defibrillation or a Triple Zero (000) call.
Related Acronyms
This guide is educational and does not replace accredited first aid training, professional medical advice, or directions from emergency services.
