Knowing what to do if someone stops breathing can mean the difference between a full recovery and a tragedy, and that knowledge does not require a medical degree. This guide walks you through the sequence of actions used in modern CPR and AED response, from the first check of the scene to handing the person off to EMS. No prior training is required to follow these steps, though enrolling in a certified CPR course will help you build the hands-on muscle memory that makes acting under pressure much easier.

Step 1: Check the Scene and the Person's Responsiveness

Before you touch anyone, take three seconds to look around. Is there oncoming traffic, exposed electrical wiring, a fire, or water nearby? If the scene is not safe for you, it is not safe for the person you are trying to help either. Moving them away from danger, when possible, should come before anything else. If you cannot safely approach, wait for professional responders or protect the area as best you can.

Once you have confirmed it is safe, kneel next to the person and check for responsiveness. Tap both shoulders firmly and shout something direct like "Are you okay?" or use their name if you know it. A firm tap, not a gentle nudge, is important because a person in cardiac arrest or experiencing a severe medical event will not respond to light touch.

If there is no response, look at the chest and abdomen for movement, and listen or feel for breath from their nose or mouth. Do this for no more than 10 seconds. This is the point where many bystanders make a critical error: mistaking agonal breathing for real breathing. Agonal gasps are irregular, noisy, and often described as snoring or gasping sounds. They are not effective breaths and are actually a sign that the person needs immediate CPR, not a reason to wait and watch. If you see no normal breathing, or you are unsure, treat it as an emergency and move to the next step without delay.

This quick assessment sets the direction for everything that follows. Rushing past it can mean missing signs that change your response, but lingering on it for too long wastes precious seconds when the brain is already being deprived of oxygen.

Step 2: Call 911 or Have Someone Else Call Immediately

If other people are present, point directly at one person and assign them the job: "You, call 911 now." Naming someone specifically prevents the bystander effect, where everyone assumes someone else is handling it. If you are alone with an adult who is unresponsive and not breathing normally, call 911 yourself before starting compressions. The dispatcher can begin guiding you immediately, and EMS needs to be en route as soon as possible.

The one exception involves children and infants. If you are alone with an unresponsive child or infant, give about two minutes of CPR first, then call 911. In pediatric emergencies, the cause is more often a breathing problem than a sudden cardiac event, so a short period of rescue care first can matter more than getting EMS on the line immediately.

Whenever possible, put your phone on speaker and set it on the ground near the person. Many 911 dispatchers are trained to walk callers through compressions step by step in real time, which is especially valuable if you have never taken a CPR class or if panic has made you second-guess your technique.

If a second person is available, send them to find an AED. Automated external defibrillators are increasingly common in offices, gyms, schools, airports, and other public buildings, often mounted in a marked wall case. Ask this helper to bring it directly to you rather than searching indefinitely, and have them alert other nearby people in case additional hands are needed. While they search, you should already be moving into position to begin hands-on care.

Step 3: Position the Person and Open the Airway

Lay the person flat on their back on a firm, stable surface. A bed or couch cushion absorbs the force of compressions, so if they are on a soft surface, move them to the floor if you can do so without injury. Keep their body straight, and if you need to roll them, support the head and neck as you turn them.

Next, open the airway using the head-tilt, chin-lift maneuver. Place one hand on the forehead and gently tilt the head back, then use two fingers of your other hand to lift the bony part of the chin upward. This moves the tongue away from the back of the throat, which is often the source of an obstructed airway in an unconscious person. If you suspect a spinal injury, such as after a fall or vehicle collision, use a jaw-thrust maneuver instead if you are trained to do so; otherwise, proceed carefully with the standard tilt, since restoring the airway takes priority.

With the airway open, quickly check inside the mouth for any visible obstruction, such as food, vomit, or a foreign object. If you can see it and reach it easily, sweep it out with a finger. Do not perform a blind finger sweep or dig around if you cannot see the object, since this can push it further down the airway.

A common mistake here is tilting the head too far or not far enough, which can leave the airway partially blocked. The chin should be lifted so the earlobe and chin form a rough line perpendicular to the ground. Getting this positioning right sets up everything that follows, whether that means rescue breaths, compressions, or both.

Step 4: Give Rescue Breaths if Trained and Comfortable

Rescue breaths are exhaled air delivered directly into a person's airway to supply oxygen when they cannot breathe on their own. If you are trained in CPR and comfortable doing so, give two rescue breaths after opening the airway. Pinch the nose shut, form a complete seal with your mouth over theirs, and give one breath lasting about one second, watching for the chest to rise. Give a second breath the same way.

Chest rise is your confirmation that air is actually entering the lungs rather than the stomach. If you do not see the chest rise on your first attempt, do not assume it failed and move on. Reposition the head, checking that the tilt and chin lift are correct, and try again. A poor seal around the mouth or an airway that is not fully open are the two most common reasons breaths do not go in.

If a second attempt still does not produce visible chest rise, do not keep trying repeatedly. Move directly into chest compressions, since maintaining blood flow to the brain and heart takes priority over perfecting the breath. You can attempt breaths again after your next set of 30 compressions.

If you are not trained in rescue breaths, or you are uncomfortable performing mouth-to-mouth on a stranger, that is not a reason to do nothing. Widely recognized public health guidance supports hands-only CPR, meaning continuous chest compressions without rescue breaths, as an effective option for bystanders who have not been trained. Oxygen already in the blood and lungs can sustain a person for a short period, and hands-only CPR keeps that oxygen circulating until EMS or a more experienced rescuer arrives. The most important thing is that compressions do not stop for long, regardless of whether breaths are part of your response.

Step 5: Begin Chest Compressions

Position yourself beside the person, kneeling at chest level. Place the heel of one hand on the center of the chest, roughly between the nipples on the lower half of the breastbone, and place your other hand on top, interlacing your fingers. Keep your arms straight and position your shoulders directly over your hands so you can use your body weight rather than just arm strength.

Push hard and fast. For adults, current guidance calls for a compression depth of at least 2 inches, allowing the chest to fully recoil between pushes. Do not lean on the chest between compressions, since incomplete recoil reduces the blood flow you are trying to generate. Depth and full recoil matter as much as speed, and shallow compressions are one of the most common mistakes bystanders make, often because they are afraid of hurting the person. Broken ribs are a real possibility with correctly performed CPR, but they are a survivable and acceptable trade-off compared to the alternative.

Maintain a rate of 100 to 120 compressions per minute. Many CPR instructors reference the tempo of "Stayin' Alive" by the Bee Gees as a rough guide, since its beat falls within that range and gives rescuers something familiar to keep pace with under stress.

If you are giving rescue breaths, cycle 30 compressions followed by 2 breaths, then repeat. If you are not trained or not comfortable with breaths, continue hands-only CPR with continuous compressions at the same rate and depth, pausing only if an AED instructs you to or another trained rescuer takes over breaths. Compressions are the single most important action in this entire sequence, and stopping them for more than a few seconds at a time, aside from AED analysis or a genuine rescuer switch, allows blood flow to the brain and heart to drop rapidly.

Step 6: Use an AED as Soon as It Arrives

An AED, or automated external defibrillator, is a portable device that analyzes a person's heart rhythm and delivers an electric shock if needed to restore a normal rhythm. As soon as it arrives, turn it on. Every modern AED gives clear voice prompts that walk you through each step, so you do not need to have used one before.

Follow the prompts to attach the adhesive pads to the person's bare chest, positioned according to the diagrams printed directly on the pads, typically one below the right collarbone and one on the lower left side of the ribs. If the chest is wet, quickly wipe it dry first, since moisture can interfere with pad contact. If the person has a heavy amount of chest hair blocking pad adhesion, most AED kits include a razor for a quick shave in the pad areas.

Once the pads are placed, the device will announce that it is analyzing the heart rhythm. This is a critical moment: make sure no one, including you, is touching the person during analysis and during shock delivery, since contact can interfere with the reading or route the shock through you. Say clearly, "Stand clear," before the shock is delivered if the AED advises one.

After the shock, or if the AED determines no shock is advised, resume chest compressions immediately. Do not wait to check for breathing or pulse. Many bystanders hesitate to use an AED, fearing they will do something wrong, but these devices are designed for untrained users and will not deliver a shock unless the heart rhythm calls for one. Using it promptly gives the person the best chance the device can offer.

Step 7: Continue Until Help Arrives or the Person Recovers

Keep cycling compressions and breaths, or continuous hands-only compressions, without stopping unless the person begins breathing normally, opens their eyes, starts moving purposefully, or otherwise shows clear signs of life. Occasional gasping, as covered earlier, does not count as normal breathing and is not a reason to stop.

CPR is physically demanding, and compression quality drops noticeably after about two minutes as fatigue sets in, even for people with strong upper body conditioning. If another capable person is present, switch out every two minutes, timing the change to coincide with a natural break in the compression-breath cycle so the interruption is as brief as possible. Communicate clearly during the switch, counting down so the new rescuer can step in without a gap in care.

Stopping too soon is one of the more common mistakes bystanders make, often because they assume a few minutes of effort is enough or because they are exhausted and unsure whether to continue. Unless EMS has arrived and taken over, or the person is clearly breathing normally on their own, continue.

When EMS arrives, be ready to hand off key information quickly: approximately when the person stopped breathing or became unresponsive, when CPR started, how many AED shocks were delivered if any, and any known medical history if you have it. This information helps the incoming medical team make faster decisions about the person's care, and it closes the loop on the actions you took under pressure.

Building Confidence Before an Emergency Happens

Reading through these steps once will not make them automatic when you actually need them. Review this sequence periodically, and think through how you would apply it in your own home, workplace, or car. Muscle memory built through hands-on practice with a manikin and an AED trainer closes the gap between knowing what to do and being able to do it under real stress.

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.