Hands-Only CPR and AED Basics: What to Do When Someone Collapses at Home or in Your Building

Quick answer: if a teen or adult suddenly collapses and is unresponsive and not breathing normally, call 911 and start Hands-Only CPR: push hard and fast in the center of the chest, about 2 inches deep, at 100 to 120 compressions a minute, letting the chest come back up after each push. Send someone for an AED, turn it on as soon as it arrives and follow its voice prompts. Keep going until responders take over or the person starts breathing normally. For infants, children, drowning and overdose victims, the American Heart Association recommends CPR with rescue breaths if you are trained.

Cardiac arrest is not the same as a heart attack. In a heart attack, blood flow to part of the heart is blocked, and the person is usually awake. In cardiac arrest, the heart’s electrical system fails, it stops pumping effectively, and the person collapses within seconds. Without help, death can follow within minutes.

The American Heart Association (AHA) reports that more than 350,000 out-of-hospital cardiac arrests happen in the United States each year, and that about 70% of them happen at home. That means the person most likely to need your CPR is someone you live with, visit or share a building with. This guide covers the basics. It is part of our apartment emergency preparedness guide, which covers kits and plans for city living.

Sources: American Heart Association, Hands-Only CPR program materials, CPR facts and statistics, and the 2020 and 2025 Guidelines for CPR and Emergency Cardiovascular Care public summaries; American Red Cross, CPR and AED steps; National Institutes of Health, National Heart, Lung, and Blood Institute, “What Is Sudden Cardiac Arrest?”; U.S. Food and Drug Administration information on automated external defibrillators. This article is general information and not a substitute for hands-on training. Call 911 in any emergency. Checked October 2026.

Recognize Cardiac Arrest

Speed matters more than certainty. The AHA and the American Red Cross describe the signs of cardiac arrest in simple terms:

• The person suddenly collapses.
• They do not respond when you tap their shoulders and shout.
• They are not breathing, or only gasping.

Gasping deserves special attention. Occasional, irregular gasps, sometimes called agonal breathing, are common in the first minutes of cardiac arrest. They are not normal breathing and should not delay CPR.

If you are unsure, start anyway. Emergency dispatchers are trained to coach callers through CPR, and the risk of doing CPR on someone who turns out not to need it is far smaller than the risk of waiting.

Step One: Call 911 and Get an AED

Call 911 right away, or point at a specific person and tell them to call. Put the phone on speaker so the dispatcher can guide you while your hands stay free.

At the same time, send someone to get an automated external defibrillator (AED). Many apartment buildings, gyms, offices, schools, transit stations and stores keep one, usually near a lobby, elevator bank or front desk. If you are alone with the person, call 911 first, then start CPR. Do not leave to search for an AED unless you know exactly where one is and it is very close.

Step Two: Hands-Only CPR for Teens and Adults

The AHA’s Hands-Only CPR is designed for bystanders who see a teen or adult collapse. It has two steps: call 911, then push hard and fast in the center of the chest.

1. Position the person on their back on a firm, flat surface. The floor is better than a bed or couch.
2. Kneel beside them and place the heel of one hand on the center of the chest, on the lower half of the breastbone. Put your other hand on top and interlock your fingers.
3. Lock your elbows and position your shoulders directly over your hands.
4. Push straight down hard, at least 2 inches for an adult, using your body weight.
5. Let the chest come all the way back up after each compression, without lifting your hands off.
6. Keep a rate of 100 to 120 compressions per minute. The AHA suggests songs with a matching beat, such as “Stayin’ Alive,” to help with timing.
7. Do not stop except to let the AED analyze or shock, or when trained responders take over.

CPR is tiring. If another person is available, switch every two minutes or so, ideally while the AED is analyzing, so compressions stay deep and fast.

Expect it to feel forceful. Ribs sometimes crack during effective CPR. That injury is survivable; untreated cardiac arrest is not.

When Rescue Breaths Matter

Hands-Only CPR is recommended for bystanders helping teens and adults who suddenly collapse. The AHA recommends conventional CPR, combining compressions with rescue breaths, in some situations:

• Infants and children
• People found unresponsive rather than seen collapsing
• Drowning victims
• Suspected drug overdoses, where breathing problems usually came first
• People who collapsed due to breathing problems

If you are trained, give breaths in these cases. If you are not trained or not comfortable giving breaths, Hands-Only CPR is still far better than doing nothing. For a suspected opioid overdose, give naloxone if it is available and keep supporting breathing and circulation until help arrives.

Infant and child CPR uses different hand positions and depths. A class is the best way to learn those differences.

Step Three: Use the AED

An AED analyzes the heart’s rhythm and, if it detects a rhythm that a shock might correct, delivers one or tells you to press a button. The FDA regulates these devices, and they are designed for use by untrained bystanders.

The steps on almost every model are the same:

1. Turn it on. Open the lid or press the power button. The AED will start giving voice instructions.
2. Expose the chest. Remove or cut clothing. Wipe the chest dry if it is wet.
3. Attach the pads as shown in the pictures, usually one on the upper right chest and one on the lower left side.
4. Stand clear while it analyzes. Make sure nobody is touching the person.
5. Deliver a shock if advised. Some models do this automatically after a warning; others ask you to press the shock button.
6. Resume CPR immediately after the shock or if no shock is advised, starting with compressions.

Expect it to reanalyze every two minutes or so and tell you what to do. Leave the pads on until responders take over.

A few safety notes from the AHA and Red Cross: move the person out of standing water before using an AED, avoid placing pads directly over an implanted device, and remove medication patches from the chest with a gloved hand. Most AEDs include child pads or a pediatric setting for young children.

Apartment-Specific Tips

Cardiac arrest in a high-rise or walk-up adds a challenge: getting responders to the right door quickly. A little planning helps:

• Know your building’s AED location. Ask management where it is and whether it is checked regularly.
• Send someone to meet responders at the street entrance and hold the elevator.
• Open and prop the door to the unit if you can do so without stopping CPR.
• Turn on the lights and clear furniture from the path to the patient.
• Tell the dispatcher the building entrance, floor, unit number and any gate or buzzer codes.

Add the AED location and building access details to your household plan. Our guide to making a family emergency communication plan has a place for both, and our guide to building an emergency plan with your neighbors explains how to share them across a building.

Your Home Kit and AED Ownership

You do not need special equipment to do Hands-Only CPR. A few items still help:

Item	Why it helps
Disposable gloves	Protects you if there is vomit or blood
CPR face shield or pocket mask	Makes rescue breaths easier and more hygienic if you are trained
Trauma shears	Cuts clothing quickly to expose the chest
Printed card with building access info	Helps you direct responders without thinking

Our checklist for a first aid kit for a small apartment has room for these.

Some households buy their own AED, especially if someone has a known heart condition. Home AEDs are available, and some require a prescription depending on the model. Talk with a doctor about whether a home unit makes sense, and check batteries and pad expiration dates on the schedule the manufacturer recommends.

Heart Attack or Cardiac Arrest? What to Do for Each

The two terms are often used interchangeably, but the response is different, and knowing which you are facing helps you act correctly.

A person having a heart attack is usually awake and breathing. The National Heart, Lung, and Blood Institute lists common warning signs: chest pain or discomfort that may feel like pressure or squeezing, pain or discomfort in the arms, back, neck, jaw or upper stomach, shortness of breath, a cold sweat, nausea and lightheadedness. Symptoms can be milder or different in women, older adults and people with diabetes.

For a suspected heart attack:

• Call 911 right away. Do not drive the person to the hospital yourself unless emergency services tell you to; paramedics can begin treatment on the way.
• Keep the person resting in a comfortable position.
• Follow the dispatcher’s instructions, which may include chewing an aspirin if the person is not allergic and has no reason to avoid it.
• Watch them closely. A heart attack can lead to cardiac arrest. If the person becomes unresponsive and stops breathing normally, start CPR and get the AED.

After the Emergency

Doing CPR on someone, whether a stranger or a family member, is intense. Afterward, many people replay what happened or wonder whether they could have done more. Those reactions are common. Remember that CPR and an AED give a person in cardiac arrest a chance they would not otherwise have, and the outcome depends on many factors outside your control.

Talk about the experience with someone you trust. Some EMS agencies and hospitals offer follow-up support for bystanders, and the 988 Suicide and Crisis Lifeline accepts calls and texts from anyone dealing with emotional distress.

If you used a building AED, tell management so they can replace the pads and check the device. If you used your own supplies, restock gloves and any face shield you opened.

Get Trained

Reading about CPR builds awareness. Practicing on a manikin builds the muscle memory you will need when adrenaline hits. The AHA and American Red Cross both offer CPR and AED courses through local training centers, hospitals, fire departments and community organizations. Many classes take only a few hours, and both organizations offer blended options that combine online learning with a short in-person skills session.

Certification from either organization is generally valid for two years. Even if you do not need a certificate for work, refreshing skills every couple of years keeps the steps fresh.

Many workplaces and schools also offer free training. Ask your employer, your building management or your local fire department.

Legal Protection for Bystanders

Fear of lawsuits keeps some people from helping. Every state has Good Samaritan laws that protect people who give reasonable emergency assistance in good faith, and many specifically cover CPR and AED use. Details vary by state, but the general purpose is to encourage bystanders to act.

Frequently Asked Questions

How fast and deep should CPR compressions be?

The AHA recommends 100 to 120 compressions per minute, at least 2 inches deep for adults, letting the chest fully recoil after each push.

Is Hands-Only CPR as good as CPR with breaths?

For a teen or adult who suddenly collapses, the AHA recommends Hands-Only CPR for bystanders. For infants, children, drowning, overdoses and breathing-related collapses, CPR with breaths is recommended if you are trained.

Can an AED shock someone who does not need it?

AEDs analyze the heart rhythm and only advise a shock for rhythms that a shock may correct. Follow the voice prompts and keep everyone clear during analysis and shocks.

What if I am not trained in CPR?

Call 911 and follow the dispatcher’s instructions. Push hard and fast in the center of the chest. Doing something is far better than doing nothing.

Where can I learn CPR?

The American Heart Association and the American Red Cross offer classes through local training centers, hospitals and fire departments, including blended online and in-person options.

The Bottom Line

When someone collapses and is not breathing normally, the steps are simple: call 911, push hard and fast in the center of the chest, and use an AED as soon as one arrives. Know where the nearest AED is in your building, plan how responders will get to your door, and take a hands-on class so your body knows what to do. Those few preparations give the people around you their best chance.