Knowing the CPR steps and procedures, in the order a rescuer performs them, gives you a clear sequence to follow when a person collapses: check, call, compress, breathe, shock. This guide walks through that sequence for adults, then marks where children and infants differ. You need no equipment or prior training to start reading. Hands-on certification is still the only way to practice compression depth and rhythm under supervision, and the techniques here are based on American Heart Association (AHA) guidance, which is updated periodically, so confirm you are learning from the current edition.

Step 1: Check the Scene and Confirm the Person Needs CPR

Before you touch anyone, look around. Traffic, fire, smoke, live wires, spilled chemicals, and unstable surroundings can turn one victim into two, and a second victim helps no one. If the scene is unsafe, call for help and move the person only if you can do it without putting yourself at risk.

Next, test responsiveness. Tap the person firmly on the shoulders and shout, "Are you okay?" For an infant, tap or flick the sole of the foot instead of shaking the body. If there is no response, you are dealing with a potential emergency.

Then look at the chest for about five to ten seconds. You are looking for two things: no breathing, or only gasping. Gasping, called agonal breathing, is an irregular, snorting, or gulping pattern that can occur in the first minutes of cardiac arrest. It is not normal breathing and it does not mean the person is fine. Treat it as a need for CPR.

A few terms are worth separating here:

Cardiac arrest: the heart stops pumping effectively, and the person collapses, stops responding, and stops breathing normally. CPR is for this.
Heart attack: a blocked blood supply to part of the heart. The person is usually awake and in pain, and can progress to cardiac arrest.

Healthcare providers may add a pulse check of up to 10 seconds while assessing breathing. Lay rescuers should not delay compressions to search for a pulse, since an untrained check is often inaccurate. If the person is unresponsive and not breathing normally, move to the next step.

Step 2: Call 911 and Get an AED

Do not shout to the room in general. Point to a specific person and give a specific order: "You in the blue jacket, call 911 and bring the AED." Assigning the task to one named or pointed-at person makes it far more likely to be done.

An AED (automated external defibrillator) is a portable device that analyzes the heart rhythm and delivers a shock if one is needed. If you are in a workplace, know in advance where yours is. Public AEDs are often found in lobbies, gyms, schools, airports, and near elevators, and they are usually in a marked wall cabinet.

If you are alone with an adult, call 911 first, put your phone on speakerphone, and place it beside you. The dispatcher can coach you through compressions while both of your hands stay free. If an AED is visibly close, fetch it, then return and begin CPR.

Being alone with a child or infant is different, because cardiac arrest in young people is more often caused by a breathing problem than by a sudden heart rhythm problem. AHA guidance has generally advised that a lone rescuer who sees a child or infant collapse suddenly should call 911 and get an AED, while a lone rescuer who finds a child or infant in a likely breathing emergency should give about 2 minutes of CPR before leaving to call. Because guidance is revised over time, confirm this against the current AHA edition, or ask your instructor, before relying on it.

Stay on the line with the dispatcher unless told otherwise. They can confirm your location and keep you on pace.

Step 3: Position the Person and Your Hands for Compressions

Compressions only work against a firm surface. Lay the person on their back on the floor or ground. If they are on a bed or couch, slide them down. Do not waste time on this if it would take long, but a mattress absorbs force that should be going into the chest.

Adult hand position

Kneel beside the person's chest. Place the heel of one hand on the lower half of the breastbone, at the center of the chest. Put your other hand on top and interlace your fingers, lifting them off the ribs so that pressure goes through the heel of the hand only.

Position your shoulders directly over your hands and lock your elbows so your arms are straight. This lets your body weight do the work instead of your arm muscles, which tire quickly. If you bend your arms, you will tire early and push too shallow.

Child hand position

Use the same location, the lower half of the breastbone. For a smaller child, one hand may be enough. For a larger child, use two hands as you would for an adult. Choose whichever method lets you reach the correct depth.

Infant hand position

For an infant, use one of two techniques:

Two fingers: place two fingers in the center of the chest, just below the imaginary line between the nipples. This is the method for a single rescuer.
Two thumbs with hands encircling the chest: place both thumbs side by side on the same spot and wrap your fingers around the ribcage and back. This is preferred when two rescuers are present, because it tends to produce better depth and blood flow.

Keep the infant on a firm surface, such as a table or the floor, and support the back if you are encircling the chest.

Step 4: Deliver High-Quality Chest Compressions

CPR does not restart the heart. It manually circulates blood, and with it oxygen, to the brain and organs until a shock or advanced care can restore a normal rhythm. That only works if the compressions are good, and quality comes down to rate, depth, recoil, and continuity.

Rate: 100 to 120 compressions per minute, for every age group. That is a little under two pushes per second. Practicing to a steady beat helps, and many instructors use songs or a metronome for this reason.

Depth:

Adults: at least 2 inches (about 5 cm).
Children: about 2 inches, or about one-third of the depth of the chest.
Infants: about 1.5 inches (about 4 cm), again roughly one-third of the chest depth.

Recoil: let the chest come fully back up after every push. Leaning on the chest, even slightly, keeps pressure inside it and reduces the blood that flows back to the heart between compressions. Keep your hands in contact with the chest, but lift your weight.

Interruptions: keep pauses under 10 seconds. Every stop drops the pressure that has been built up, and it takes several compressions to restore it. The most common mistakes are pushing too shallow, pushing too slowly, and stopping to reassess when nothing has changed.

Pushing hard is tiring. Rescuers lose effectiveness within a couple of minutes, often without noticing. If someone else is present and trained, switch compressors about every 2 minutes, and make the swap in a few seconds.

You may feel or hear ribs crack, particularly in older adults. This is common and is not a reason to stop. A broken rib heals, while an unperfused brain does not.

Step 5: Give Rescue Breaths If You Are Trained

If you are trained and willing, pair compressions with breaths. For a single rescuer, the ratio is 30 compressions followed by 2 breaths, at every age. With two rescuers on a child or infant, the ratio changes to 15 compressions to 2 breaths, because the arrest is more likely to be breathing related and ventilation matters more.

To give breaths:

Open the airway with a head tilt and chin lift. Healthcare providers who suspect a spine injury should use a jaw thrust instead. For an infant, keep the head in a neutral or slightly sniffing position rather than tilting it far back.
Seal your mouth over the person's mouth and pinch the nose closed. For an infant, cover both the mouth and nose with your mouth. A pocket mask or other barrier device is better if you have one.
Give each breath over about 1 second, with just enough air to make the chest visibly rise.
Take your mouth away, let the chest fall, and give the second breath.
Return to compressions right away.

Do not over-ventilate. Big, forceful, or rapid breaths push air into the stomach and raise pressure in the chest, which reduces blood flow back to the heart. A child or infant needs a smaller puff than an adult.

If a breath does not make the chest rise, reposition the head to reopen the airway and try once more. Do not spend more than a few seconds on this before resuming compressions.

If you are untrained, uncomfortable giving mouth-to-mouth, or have no barrier device, hands-only CPR is acceptable for an adult in cardiac arrest. That means continuous compressions at 100 to 120 per minute until help arrives. Children and infants more often need breaths, so use them if you are trained.

Step 6: Use the AED as Soon as It Arrives

The moment an AED is at your side, turn it on and follow its voice prompts. Do not stop compressions while you open the case or power up the device. If a second person is available, one rescuer keeps pushing while the other applies the pads.

Pad placement for an adult is on the bare chest: one pad on the upper right chest below the collarbone, and the other on the lower left side, below the armpit. Pictures on the pads show the position.

For a child under 8, use pediatric pads or a pediatric setting if the AED has one. If these are not available, adult pads are acceptable, and using an AED is better than not using one. For small children and infants, the pads may need to go on the front and back of the chest so they do not touch each other.

Prepare the skin quickly:

Dry a wet chest with a towel or shirt.
Remove any medication patch from the pad area and wipe the skin.
If heavy chest hair prevents the pads from sticking, press down firmly, and if that fails, shave the area quickly with the razor included in many AED kits.

When the AED says it is analyzing, say "Clear" and make sure no one is touching the person. If a shock is advised, check once more that everyone is clear, then press the shock button if the device does not deliver it automatically.

Resume compressions immediately after the shock. Do the same if the AED says "no shock advised," because that message does not mean the person is fine. The device will prompt another rhythm check about every 2 minutes. Leave the pads on the chest until responders arrive.

Step 7: Continue Until Help Takes Over, Then Get Trained

Keep going until one of these happens:

Emergency responders take over.
The person clearly begins breathing normally or moves purposefully.
An AED instructs you to stop.
You are physically unable to continue.

If the person starts breathing but remains unresponsive and has no obvious injury, roll them onto their side in the recovery position, with the top knee bent and the head tilted slightly back to keep the airway open. Stay with them and monitor their breathing. Be ready to restart CPR if it stops.

When responders arrive, give them a brief report: what you saw, how long you performed CPR, and whether an AED shock was delivered. These details guide their next decisions.

CPR guidelines are revised periodically by the AHA, and compression rates, ratios, and sequences can change between editions. Before you rely on any written guide, including this one, check which edition your instructor teaches and the date it took effect.

Reading about CPR is not a substitute for practicing it. Best Choice CPR offers CPR/AED, First Aid, and Basic Life Support (BLS) courses, with BLS designed for healthcare providers. Classes include hands-on skills practice, and certifications typically run on a two-year renewal cycle. Confirm current course details and schedules before you enroll, as these can change.

Responding With Confidence: Your Next Move After Learning CPR

The sequence is short enough to remember: check the scene and the person, call 911 and send for an AED, compress hard and fast, add breaths if you are trained, and shock as soon as the device is ready. What reading cannot give you is the feel of 2 inches of depth, a steady pace under pressure, or a smooth handoff between rescuers. Those come only from practice with an instructor watching.

Don't wait until an emergency happens. Equip yourself with life-saving CPR skills that could make all the difference when seconds count. Register for a certification class today and gain the confidence to respond when someone needs help most. If you already hold a card, check its expiration date and renew before it lapses so your skills stay current.