To resuscitate someone who has collapsed and isn’t breathing, push hard and fast in the center of their chest at a rate of 100 to 120 compressions per minute. This is the single most important action you can take. The American Heart Association recommends that untrained bystanders perform hands-only CPR (no mouth-to-mouth needed) until paramedics arrive. If you’re trained in CPR, alternate 30 chest compressions with 2 rescue breaths.
The sequence to remember is C-A-B: compressions, airway, breathing. Compressions come first because restoring blood flow to the brain and heart is the top priority. Every minute without CPR reduces the chance of survival.
Chest Compressions Step by Step
Place the person on their back on a firm, flat surface. Kneel beside them. Put the heel of one hand in the center of their chest, between the nipples, and place your other hand on top, fingers interlocked. Lock your elbows, position your shoulders directly over your hands, and push straight down at least 2 inches deep. Don’t compress deeper than 2.4 inches, as that can cause injury. Let the chest fully recoil between each push.
Aim for 100 to 120 compressions per minute. That’s roughly the tempo of the song “Stayin’ Alive.” Keep going without stopping until an ambulance arrives, an AED becomes available, or the person starts breathing on their own. If someone else is nearby, take turns every two minutes so neither of you gets too fatigued to compress effectively.
Adding Rescue Breaths
If you’re trained and comfortable giving rescue breaths, do 30 compressions followed by 2 breaths, then repeat. To deliver a breath, tilt the person’s head back gently by pressing on their forehead and lifting their chin. This opens the airway. Pinch their nose shut, seal your mouth over theirs, and blow steadily for about one second. Watch for the chest to rise. Give a second breath, then return immediately to compressions.
If you’re not trained or uncomfortable with mouth-to-mouth, skip it entirely. Hands-only CPR is the recommended approach for untrained bystanders and is far better than doing nothing. Many people hesitate to start CPR because they’re worried about the breathing part. Continuous chest compressions alone still circulate oxygenated blood and dramatically improve survival.
Using an AED
An automated external defibrillator (AED) is the device found in wall-mounted cases at airports, gyms, offices, and schools. It analyzes the heart’s rhythm and delivers an electric shock if needed. An AED does not replace CPR. It works alongside it.
If someone nearby can grab an AED, don’t stop compressions while they retrieve it. Once the AED arrives, turn it on. It will give you voice prompts for every step. Remove all clothing from the person’s chest, including anything with metal like an underwire bra. Peel the adhesive pads from the packaging and place one on the upper right side of the chest and the other on the lower left side. The AED will analyze the heart rhythm automatically. If it advises a shock, make sure no one is touching the person, then press the shock button. Immediately resume CPR afterward. The AED will continue to check the rhythm and tell you if another shock is needed.
CPR for Infants and Children
The compression rate is the same for all ages: 100 to 120 per minute. What changes is how much force you use, how deep you compress, and what part of your hands you use.
- Infants (under 1 year): Use two fingers (or both thumbs with your hands wrapped around the chest if a second rescuer is present). Compress about 1.5 inches deep, roughly one-third of the chest depth. Support the baby on a firm surface or your forearm.
- Children (age 1 through puberty, or under about 55 kg): Use one or two hands depending on the child’s size. Compress about 2 inches deep, again roughly one-third of the chest. For a small child, one hand may be enough.
A solo rescuer uses the same 30:2 compression-to-breath ratio as with adults. If two rescuers are present for a child or infant, switch to 15 compressions followed by 2 breaths. Rescue breaths are more important in pediatric resuscitation than in adults because children’s cardiac arrests more often stem from breathing problems rather than heart rhythm issues.
Drowning Resuscitation
Drowning is one situation where rescue breaths become critical. A drowning person’s heart typically stops because they’ve been deprived of oxygen, so restoring breathing is just as important as restoring circulation. The 2024 American Heart Association guidelines emphasize airway management and ventilation as priorities in drowning cardiac arrest.
Once the person is on dry land or in a boat, trained rescuers can start with rescue breaths before compressions (A-B-C instead of the usual C-A-B) or follow the standard compression-first sequence. Either approach is acceptable. If you’re trained and conditions are safe, in-water rescue breathing before reaching shore may help prevent the situation from progressing to full cardiac arrest. If you’re untrained, start chest compressions as you would for any other emergency and keep going until help arrives. Do not attempt to drain water from the lungs. There’s no need to stabilize the neck unless there’s reason to suspect a diving or impact injury.
Opioid Overdose
Opioid overdoses look different from sudden cardiac arrest. Signs include unconsciousness, extremely slow or shallow breathing (or no breathing at all), gurgling or choking sounds, bluish or grayish skin especially around the lips and fingernails, and pinpoint pupils that don’t react to light.
If you have naloxone (commonly sold under the brand name Narcan), administer one dose immediately, then call 911. Naloxone is available as a nasal spray and can restore normal breathing within 2 to 3 minutes by blocking the effects of opioids in the brain. If breathing doesn’t improve after 2 to 3 minutes, give a second dose. While waiting for the medication to take effect, try to keep the person awake and breathing. Lay them on their side to prevent choking on vomit. If they stop breathing entirely and have no pulse, begin CPR. Stay with them until paramedics arrive, because naloxone wears off faster than many opioids, and breathing can slow again.
The Recovery Position
If someone is unconscious but breathing normally, they don’t need CPR. They need to be placed on their side so their airway stays clear. This is called the recovery position.
Kneel beside the person while they’re on their back. Take the arm closest to you and extend it out at a right angle from their body, palm facing up. Fold their other arm across their chest so the back of that hand rests against the cheek nearest you, and hold it there. With your free hand, bend their far knee up to a right angle. Pull that bent knee toward you to roll them gently onto their side. Their head should now rest on the hand you placed against their cheek, and their bent leg keeps them stable. Tilt their head back slightly and lift the chin to keep the airway open. Stay with them and monitor their breathing until help arrives.
Legal Protection for Bystanders
All 50 U.S. states and Washington, D.C., have Good Samaritan laws that protect people who voluntarily help in an emergency. These laws shield you from negligence claims as long as you’re acting in good faith, not expecting payment, and not being recklessly careless. If the person is unconscious, the law assumes implied consent, meaning you don’t need permission to begin CPR. If the person is conscious and responsive, ask before helping.
Good Samaritan laws cover ordinary mistakes, like a cracked rib from compressions (which is common even when CPR is performed correctly). They do not cover intentional harm or gross negligence. The legal framework exists specifically to encourage bystanders to act. A person in cardiac arrest who receives no CPR has a far worse outcome than one who receives imperfect CPR.