Every year some 350,000 people suffer cardiac arrest—when the heart suddenly stops working—away from the relative safety of a hospital. Whether they receive cardiopulmonary resuscitation right away can mean the difference between life and death.

Research—including a large Swedish study, published today in the journal Circulation—has found that the willingness of bystanders to perform CPR can result in a twofold increase in a victim’s chance of survival. 

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But research also shows that many people are afraid to jump in and help. Less than a third of people who go into sudden cardiac arrest receive CPR from a bystander, according to recent studies.

Experts report that people hesitate to do CPR because they haven’t had training, are afraid of doing it wrong, or even fear they might get sued if they cause an unintentional injury.

But thanks to Good Samaritan laws in every state, you can’t be sued if you act in good faith in an emergency. “And the risk of injuring someone is quite low; you can really only make them better, not worse,” says Jonathan L. Epstein, senior director of science and content development for the American Red Cross.

For this reason, experts say fear and even a lack of formal training shouldn’t stop you from intervening in an emergency. In fact, evidence has emerged in the past 10 years that a technique called “hands-only CPR,” where you do chest compressions without mouth-to-mouth resuscitation, can be just as effective as doing both.

Cleveland Clinic survey released in 2018 found that while more than half of Americans said they knew CPR, only 1 in 6 knew that hands-only CPR is a recommended method. And only about 1 in 10 of the 1,000 people surveyed knew the correct beat pace for compressions.

Hands-only CPR is much less complicated, making it a good choice if you have limited (or even zero) training. Here’s what you should know the next time you have an opportunity to save someone’s life.

A Simpler Way to Do CPR

“We want to get the message out to the public that doing anything is far superior to doing nothing,” Epstein says. “If you’re more comfortable doing the hands-only technique, that can help buy the victim precious minutes until the ambulance arrives.”

A growing stack of evidence, including a 2017 review of the research from the Cochrane Collaboration, an independent panel of experts, supports this approach.

A 2010 study published in The New England Journal of Medicine looked at 1,941 people who went into cardiac arrest outside of a hospital. Roughly half were given traditional CPR (chest compressions plus rescue breaths) by bystanders who were guided by a 911 dispatcher. The other half were given just chest compressions by bystanders who were guided by a 911 dispatcher.

“We observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge,” the authors wrote.

In the new Swedish study, researchers looked at more than 30,000 cases of people who had bystander-witnessed, out-of-hospital cardiac arrest. Those who received CPR with rescue breaths had slightly better outcomes than those who received hands-only CPR, but "any type of CPR was associated with doubled survival rates in comparison with no CPR," the authors concluded.

Another benefit of the hands-only technique is accessibility.

“Getting full CPR training is a barrier for many people, and older people, as a group, are much less likely to be trained,” says Benjamin S. Abella, M.D., director of the Center for Resuscitation Science at the University of Pennsylvania and author of a recent study on age disparity in CPR training. While the mean age of sudden cardiac arrest victims is around 64, people 60 and older are about 50 percent less likely to be trained in CPR compared with those younger than 49, Abella says. Teaching hands-only CPR could help increase knowledge and confidence in all age groups.

“The barriers are much lower for learning the hands-only technique,” Abella says. In fact, he says that when people who took a full CPR certification course and others who took an abbreviated 30-minute class on the hands-only technique were tested 30 days later, both had retained similar skills. 

CPR: Putting It Into Action

It’s important to note that hands-only CPR is to be used only on adults and teenagers. The recommended technique for younger children and babies still includes both chest compressions and rescue breaths. But don’t hesitate to use hands-only CPR on everyone else. Just keep these tips in mind: 

Know the signs. “If someone collapses in front of you and they’re unresponsive when you yell at them or tap them on the shoulder, you should call 911 and immediately start chest compressions,” Epstein says.

Don’t go at it alone. Epstein recommends putting your phone on speaker and placing it right next to the victim, so that you are able to speak to a 911 dispatcher and receive directions without stopping compressions.

Keep the beat. “You want to push down on the center of the chest, hard and fast, trying to compress at least 2 inches down,” Epstein says. The goal is to work at a pace that allows for 100 compressions per minute. You can get a metronome app on your phone that will keep the beat, or try singing the Bee Gees “Stayin’ Alive” (a song with 100 beats per minute) and compressing in time to the song.

Refresh your knowledge. You can perform hands-only CPR with nothing more than the help of a 911 dispatcher, but if you want to have more confidence in your skills, a brief training course—or even a review of all the steps involved—might help. Check out the American Heart Association and the Red Cross for a list of courses as well as videos and step-by-step directions for performing hands-only CPR technique.