How to Do CPR
Recognize cardiac arrest in an adult, get 911 and an AED on the way, and give hands-only chest compressions at the right depth and rate until help arrives, plus what changes for children and infants.
You will end up knowing how to recognize cardiac arrest, get 911 and an AED on the way, and push hard and fast enough on the chest to keep blood moving to the brain until help arrives, along with what changes for children and infants.
About 356,000 adults in the United States are treated by emergency services for a cardiac arrest outside a hospital each year, according to the American Heart Association's 2025 guidelines, and only about 1 in 10 survive to leave the hospital. When the heart stops, blood stops reaching the brain, and every minute without help counts against the person. Ambulance response times vary widely from one area to the next, so expect to be alone with the person for several minutes at least.
That gap is where bystander CPR saves lives. The AHA reports that immediate CPR can double or triple a person's chance of survival. Yet the same guidelines show bystanders gave CPR in only 47.7% of adult cardiac arrests outside the hospital in 2024.
If you are hesitating because you are not sure you would do it right, remember that imperfect CPR is vastly better than no CPR. If someone is unresponsive and not breathing normally, they are already in the worst possible situation. You cannot make it worse by trying.
The steps below teach hands-only CPR, chest compressions without mouth-to-mouth breathing. The 2025 adult guidelines call a compression-only approach appropriate when a bystander is untrained or unwilling to give breaths.
Check for responsiveness and call 911
If you see someone collapse or find someone unconscious, first make sure the scene is safe for you (no live electrical wires, traffic, or other hazards). Tap the person firmly on both shoulders and shout "Are you okay?" If they do not respond, call 911 immediately or tell someone specific to call. Say "You in the red shirt, call 911 now." Naming one person means nobody assumes someone else is calling. If anyone else is there, send them to find an AED (step 6). If you are alone, call 911 first, put the phone on speaker, and then start CPR, which is the order the 2025 guidelines give a lone rescuer. The dispatcher will stay on the line and guide you through the process if needed.
Heads up: Do not waste time checking for a pulse unless you are trained to do so. Pulse checks are unreliable for untrained rescuers and waste precious seconds. If the person is unresponsive and not breathing normally (no breathing, gasping, or only occasional gasps), begin CPR immediately.
Start compressions where the person is
Roll the person onto their back and kneel beside their chest, roughly at nipple level. A firm surface is better, because a mattress absorbs some of the force you put into the chest. But do not delay compressions to find one. The 2025 adult resuscitation guidelines say to resuscitate a person where they are found, as long as you can give good compressions there safely, because delays to CPR are linked to worse survival. If they collapsed on a bed, kneel on the bed beside their chest and start there, since the guidelines note that kneeling next to the person gives deeper compressions than standing. Move them to the floor only if the bed is so soft that you cannot push the chest down at least 2 inches. Remove any thick clothing covering the chest if you can do it quickly, but do not waste time with zippers, bras, or buttons that take more than a few seconds. Compressions work through clothing. If the person is wearing a heavy winter coat, open or remove it if possible because the bulk absorbs compression force and reduces effectiveness. Speed matters more than perfection here. Every second without compressions is a second without blood flow to the brain.
Place your hands in the correct position
Put the heel of one hand on the center of the person's chest, on the lower half of the breastbone (sternum). Place your other hand on top of the first, interlocking your fingers. Keep your fingers lifted off the chest so that only the heel of your bottom hand is pressing on the sternum. Straighten your arms and lock your elbows. Position your shoulders directly above your hands so you can push straight down using your body weight rather than arm strength alone. This position is critical for effective compressions and for preventing fatigue. Keep your hands off the upper chest near the collarbone, where compressions do less. Keep them off the soft area at the very bottom of the breastbone too, because the 2025 guidelines note that compressing over its tip (the xiphoid) may be less effective. The correct spot is between the nipples, on the hard bone in the center of the chest.
Push hard and fast, 100 to 120 times a minute
Press down at least 2 inches into the chest, and no more than about 2.4 inches. The 2025 AHA guidelines call anything deeper than that excessive and tell rescuers to avoid it. Push hard. It takes more force than you expect, and you may feel or hear ribs cracking. This is normal in CPR and does not mean you should stop. Cracked ribs heal. Cardiac arrest without CPR does not. Push at a rate of 100 to 120 compressions per minute. Keep time to the beat of "Stayin' Alive" by the Bee Gees, which falls in that range. "Baby Shark" and the Imperial March from Star Wars work too. Let the chest fully recoil (come back up completely) between each compression. Do not lean on the chest between compressions. Full recoil allows the heart to refill with blood between pushes.
Continue without stopping until help arrives
Keep compressions going until professional help arrives and takes over, the person shows obvious signs of life (moving, breathing normally, coughing), or you are physically unable to continue. Keep every other pause short, whether it is a handoff to another rescuer, rescue breaths if you give them (step 7), or the AED's rhythm check and shock (step 6). CPR is physically exhausting. If another person is available, switch every 2 minutes, even if you do not feel tired yet. The 2025 guidelines call a 2-minute rotation sensible because it keeps compressions deep enough. The person being relieved should count to ensure minimal interruption during the switch. Aim for less than 10 seconds of interruption during the handoff. If you are alone, keep going. Tired CPR is still better than no CPR. Expect to be doing CPR for several minutes, possibly many, before paramedics arrive. That feels like a very long time when you are doing it. Your arms will burn, your back will ache, and you will wonder if it is working. Keep pushing. CPR does not restart the heart by itself in most cases. It keeps oxygenated blood circulating to the brain until a defibrillator or advanced medical intervention can restore a normal heart rhythm. You are buying time.
Use an AED if one is available
An AED (Automated External Defibrillator) is a device that can shock the heart back into a normal rhythm. AEDs are found in many public buildings, airports, gyms, schools, and offices, usually in a wall-mounted case. If someone brings you an AED, turn it on and follow the voice prompts. The device tells you exactly what to do. Open the pads, peel the backing, and place them on the person's bare chest as shown in the diagram on the pads (one on the upper right chest, one on the lower left side). When the AED says it is analyzing the heart rhythm, stop compressions and make sure nobody is touching the person. If it advises a shock, keep everyone clear, press the shock button, then resume compressions immediately. If it advises no shock, resume compressions immediately. The 2025 guidelines say these pauses should be as short as possible. The AED's rhythm check is also the natural moment to switch rescuers, which is why step 5 rotates every 2 minutes. AEDs are designed for untrained users. You cannot shock someone who does not need it because the device analyzes the rhythm first.
Good to know: Send someone to look for an AED as soon as you begin CPR. Do not stop compressions to search for one yourself. If a bystander brings one, they can set it up while you continue chest compressions. Minimize any pause in compressions.
Know what hands-only CPR cannot cover
Hands-only CPR (compressions without rescue breaths) is recommended for untrained bystanders performing CPR on adults. It is effective because the blood still contains oxygen for several minutes after cardiac arrest, and compressions circulate that oxygenated blood to the brain. For drowning victims, children, and infants, rescue breaths are more important because the cause is often respiratory (not enough oxygen) rather than cardiac. If you are trained and willing, give two rescue breaths after every 30 compressions: tilt the head back, lift the chin, seal your mouth over theirs, and blow for 1 second until you see the chest rise. If you are not trained or not comfortable with rescue breaths, continuous hands-only compressions are still highly effective for adult cardiac arrest. Child CPR (ages 1 to puberty) uses the same technique with less force. Use one hand instead of two on a smaller child and compress about 2 inches, which is roughly a third of the depth of their chest. Infant CPR (under age 1) changed in 2025. The 2025 AHA and American Academy of Pediatrics guidelines dropped the old two-finger method, because it was not effective at reaching the proper depth. They recommend either the heel of one hand, or wrapping both hands around the infant's chest and compressing with your thumbs. Aim for about 1.5 inches, again roughly a third of the chest. For a child or an infant, attach the AED as soon as it arrives, with pediatric pads or a pediatric attenuator if it has them, as the 2025 pediatric guidelines advise. If you suspect an opioid overdose and someone brings naloxone, the 2025 guidelines say giving it may be reasonable as long as high-quality CPR is not interrupted, so have a second person give it while you keep pushing. Naloxone reverses the drug. It does not restart a heart that has already stopped, so the compressions carry on either way.
Find out today where the AEDs are at your workplace, your gym, and any building you spend a lot of time in, so you know where to send someone. Then take a formal CPR certification course through the American Red Cross. A short in-person class gives you hands-on practice and covers scenarios this guide cannot replicate. Until then, if you ever need to give CPR, tell the 911 dispatcher and follow their coaching, as FAQ 4 below explains.
Questions we get asked about this
Answers from experience, not a textbook.
You may crack ribs. This is common and expected, especially in older adults. Cracked ribs heal. A person in cardiac arrest will die within minutes without CPR. The risk of rib injury is vastly outweighed by the benefit of circulating blood to the brain. You cannot make a cardiac arrest victim worse by performing CPR. If they are unresponsive and not breathing, they need compressions regardless of the risk of minor injury. You might also see the person gasp, make gurgling sounds, or even vomit during CPR. These are reflexes, not signs of recovery. Do not stop compressions for gasping. If the person vomits, turn their head to the side to clear the airway, wipe the mouth if you can, and resume compressions immediately.
All 50 US states and the District of Columbia have Good Samaritan laws that protect people who provide emergency care in good faith. They cover the ordinary mistakes of someone doing their best in an emergency, and they fall away only for gross negligence or willful misconduct, meaning a conscious disregard for someone's safety rather than imperfect technique under pressure. The laws exist to encourage bystanders to help without fear of liability. Outside the US, the rules differ by country.
If a person is unresponsive (does not react when you tap their shoulders and shout) and is not breathing normally (no breath, gasping, or only occasional irregular gasps), they need CPR. Do not wait to see if they "come around." Do not spend time checking for a pulse unless you are trained. Normal snoring or heavy breathing in an unconscious person is not the same as gasping. Gasping looks like a fish out of water: irregular, infrequent, ineffective attempts to breathe. When in doubt, start CPR. If the person does not need it, they will quickly show signs of life (movement, coughing, pushing you away) and you stop. Starting CPR on someone who does not need it is far less dangerous than not starting it on someone who does.
Yes. The American Heart Association explicitly recommends that untrained bystanders perform hands-only CPR (chest compressions without rescue breaths) on any adult who collapses and is not breathing normally. Formal training is valuable for building confidence and practicing technique, but it is not required to save a life. Push hard, push fast, on the center of the chest. That is enough. The 911 dispatcher will also guide you through the steps over the phone if you are unsure. Tell them you are performing CPR and they will coach you through it in real time until paramedics arrive.