Written by Tom Sirmons

When someone suffers sudden cardiac arrest, the person standing nearby may be their best chance of survival.

Cardiac arrest happens when the heart suddenly stops pumping blood effectively. Within seconds, the person usually becomes unresponsive and stops breathing normally. Without blood flow, the brain and other vital organs quickly begin to suffer damage.

That is why CPR shouldn’t wait for an ambulance.

More than 350,000 cardiac arrests occur outside hospitals in the United States each year. Immediate CPR can double or even triple a person’s chance of survival, according to the American Heart Association.

Yet bystanders still begin CPR in only about 40% of out-of-hospital cardiac arrests.

Those numbers make CPR training much more than something healthcare workers need to know.

The person next to you may be the one who needs CPR

One of the most important CPR statistics is easy to overlook: most cardiac arrests outside a hospital don’t happen in airports, shopping malls or other crowded public places.

They happen at home.

The American Heart Association reports that more than 70% of out-of-hospital cardiac arrests occur in homes or residences.

That means the person who needs your CPR skills may not be a stranger.

It could be your spouse, parent, child, friend or another family member.

Learning CPR isn’t only about being prepared for an emergency at work. It gives you the ability to respond when someone close to you suddenly collapses and professional help has not yet arrived.

You don’t need to wait for paramedics

Calling 911 is one of the first things that should happen during a suspected cardiac arrest, but calling for help doesn’t mean standing by until emergency responders arrive.

If a teen or adult suddenly collapses, is unresponsive and isn’t breathing normally, an untrained bystander can begin Hands-Only CPR while someone calls 911 and retrieves an AED if one is available.

Hands-Only CPR has two basic steps:

Call 911, then push hard and fast in the center of the chest.

For adults, current American Heart Association guidance calls for chest compressions at a rate of 100 to 120 compressions per minute.

The goal is to keep some blood circulating to the brain, heart and other organs until an AED or emergency medical professionals can provide additional treatment.

Recent research continues to show the importance of acting early. A study highlighted by the American Heart Association found that beginning bystander CPR within the first 10 minutes after cardiac arrest was associated with substantially better survival and neurological outcomes compared with receiving no bystander CPR.

The sooner CPR begins, the better.

Hands-Only CPR doesn’t mean rescue breaths are outdated

This is an area where CPR advice has sometimes become confusing.

You may have heard that mouth-to-mouth breathing is no longer part of CPR. That isn’t entirely correct.

For an untrained bystander who witnesses a teen or adult suddenly collapse, Hands-Only CPR is a simple and effective response. It removes some of the hesitation people may feel about rescue breathing and gets chest compressions started quickly.

People who are trained in conventional CPR can still provide 30 chest compressions followed by 2 rescue breaths for an adult in cardiac arrest.

Rescue breaths are especially important in situations where the cardiac arrest may have resulted from a breathing problem, including many emergencies involving infants and children, drowning, drug overdose or respiratory failure.

The important point isn’t deciding which CPR method is “better” in every possible situation.

It’s starting CPR.

Doing something quickly is far better than standing nearby because you’re afraid you’ll perform CPR imperfectly.

Good chest compressions require more force than many people expect

Watching CPR on television doesn’t give you a very realistic idea of what proper chest compressions feel like.

For an average adult, the American Heart Association recommends compressing the chest at least 2 inches deep, while avoiding excessive compression depths greater than about 2.4 inches. Compressions should be delivered at 100 to 120 per minute while allowing the chest to fully recoil between compressions.

That’s harder work than many first-time CPR students expect.

After performing continuous compressions for a couple of minutes, rescuers can become tired enough that compression depth starts to decrease. Current AHA guidance supports rotating compressors approximately every two minutes when another trained rescuer is available.

This is one reason hands-on CPR training is valuable. Reading the instructions and physically performing two minutes of compressions on a manikin are very different experiences.

Don’t forget the AED

CPR buys time. An automated external defibrillator, or AED, may be able to treat the abnormal heart rhythm that caused the cardiac arrest.

If an AED is available, someone should retrieve it while another person continues CPR.

Modern AEDs analyze the person’s heart rhythm and determine whether a shock is appropriate. The rescuer doesn’t need to diagnose the rhythm.

The American Heart Association’s Chain of Survival emphasizes both immediate CPR and rapid defibrillation because these actions can take place before professional rescuers arrive.

This is why schools, workplaces, churches, gyms and public facilities should not only have AEDs but make sure people know where they are located.

An AED hidden in a locked office isn’t very useful when someone collapses across the building.

What if you’re afraid of hurting someone?

Fear is one of the biggest reasons people hesitate to perform CPR.

People worry about breaking a rib, doing the compressions incorrectly or somehow making the situation worse.

But consider what cardiac arrest actually means.

The person’s heart is no longer effectively pumping blood. Without CPR and other emergency treatment, the situation will be fatal.

The American Heart Association specifically encourages bystanders not to let fear prevent them from acting. The potential benefit of CPR greatly outweighs the risk of injury.

If you’re unsure what to do, call 911 and put the phone on speaker. Emergency dispatchers can provide CPR instructions while help is being sent.

CPR skills are worth refreshing

CPR guidelines change as researchers learn more about resuscitation, but that doesn’t mean CPR training you completed several years ago suddenly becomes useless.

What does change is technique, terminology and emphasis.

The American Heart Association released updated CPR and Emergency Cardiovascular Care Guidelines in 2025 based on the latest resuscitation research.

If you haven’t practiced CPR for a while, a refresher class can help restore confidence and reinforce important details such as compression depth, compression rate, AED use and minimizing interruptions.

CPR is a physical skill. Like most physical skills, it is easier to perform under pressure when you’ve practiced it.

You may never need CPR training, but you may be very glad you have it

Nobody takes a CPR class hoping for the opportunity to use what they learned.

Most people will hopefully never have to perform CPR outside the classroom.

But cardiac arrest doesn’t provide advance notice. It can happen at home, during a sporting event, at work, in a restaurant or while spending time with friends.

If it does, the minutes before emergency medical professionals arrive belong to the people already there.

Call 911.

Start CPR.

Get an AED if one is available.

And keep going until professional rescuers take over or the person begins showing signs of life.

Bystander CPR isn’t a replacement for emergency medical care. It is the critical bridge that can keep someone alive long enough to receive it.

Editor’s note: This article was originally published previously and was reviewed and updated in 2026 to reflect current CPR research, the 2025 American Heart Association CPR and Emergency Cardiovascular Care Guidelines, and additional educational content.