Gasping Is Not Breathing: How to Recognise Cardiac Arrest
A person whose heart has stopped often keeps gasping for a while, and it fools people into waiting. How to tell normal breathing from the kind that means CPR.
Jarrett Chisholm, ACP · October 8, 2026 · clinically reviewed by Jarrett Chisholm, ACP
The most common reason a bystander does not start CPR on a person in cardiac arrest is not fear, and it is not a lack of training. It is that the person looked like they were breathing. Their chest moved. They made a sound. Somebody said they are still breathing, and everyone waited for the ambulance.
Image needed · hero
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Close-to-medium shot. An adult man lies on his back on a hallway or office floor. A kneeling bystander has one hand on his shoulder and has turned their face toward his chest, eyes on it, clearly counting. Calm, focused expression. Neutral lighting, no blood, no equipment yet.
Alt text ready: “A bystander kneels beside an unresponsive man lying on his back, one hand on his shoulder, looking closely at his chest to check his breathing.”
What they were seeing was very likely agonal breathing: slow, irregular gasps that happen after the heart has stopped. The American Heart Association's 2025 guidelines describe it as common, present in up to 40 to 60 percent of out-of-hospital cardiac arrests, and name it as one of the usual reasons lay rescuers fail to recognise an arrest and delay compressions.
This post is about that single judgement: is this person breathing normally? It is the question that decides whether you start CPR, and getting it right is worth more than any other skill in the first minute. It is also a question you can answer without any equipment and without touching a pulse. the rest of what the first minute asks of a bystander.
What agonal breathing is, and why it happens
When the heart stops pumping, the brain stops receiving oxygen. For a short time afterwards, the lower part of the brain that controls breathing can still fire off reflex gasps. They are not real breaths. They move little or no air, they are not regular, and they do nothing to oxygenate the blood, because there is no circulation to carry oxygen anywhere even if some air gets in.
To an untrained eye these gasps look like life, and in a sense they are: they are a sign that the brain was working very recently. That is exactly why they matter. A person making agonal gasps has often only just gone into arrest, which is the moment when CPR and a defibrillator have the best chance of working. The gasps fade the longer the arrest goes on.
What they sound and look like varies. People describe snoring, snorting, a gulp, a sigh, or the jaw moving as if the person is trying to take a breath. They are often several seconds apart and irregular. The Canadian Red Cross first aid manual calls it agonal respiration and gives the rule plainly: care for the person as if they are not breathing.
How to check, and for how long
Check responsiveness first. Tap the person's shoulders firmly and speak loudly: are you okay? A person who does not respond at all is unresponsive, and that alone means 911 should be called and a defibrillator sent for.
Then look at the breathing for 5 to 10 seconds. You are looking for normal breathing: a regular, even rise and fall of the chest, with air clearly moving in and out. Someone who can speak, cry or moan is breathing. Someone who gasps once in ten seconds, or makes an irregular snoring sound with no regular rhythm, is not breathing normally.
| What you see | What it means | What you do |
|---|---|---|
| Regular, even breaths, chest rising and falling | Breathing normally | Call 911 if unresponsive, keep the airway open, recovery position |
| Occasional gasps, snorts or gulps, seconds apart | Agonal breathing, not real breathing | Call 911, start CPR, get a defibrillator |
| No movement of the chest at all | Not breathing | Call 911, start CPR, get a defibrillator |
| Not sure which of these it is | Treat as not breathing normally | Call 911, start CPR, get a defibrillator |
Do not stretch the check out past ten seconds hoping to be sure. You will not become more certain by waiting, and every second counts against the person. If you are unsure whether what you are seeing is normal, treat it as not normal.
No, no, go
Heart and Stroke's Canadian edition of the 2025 guideline highlights repeats a simple way to make this decision, often called no, no, go. Is the person responsive? No. Are they breathing normally? No. Go: call, start compressions, get the defibrillator.
Image needed · diagram
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Three boxes left to right joined by arrows, Delta gold and charcoal. Box one: Responsive? with NO. Box two: Breathing normally? with NO, and a small note underneath that gasping counts as no. Box three, larger and gold: GO, listing call 911, start compressions, get a defibrillator. Plain sans serif, no clip art.
Alt text ready: “A three-step decision diagram: responsive? no. breathing normally? no. go: call 911, start compressions, get a defibrillator.”
Notice what is not in that sequence. There is no pulse check for lay rescuers. Current guidance has recognition by bystanders based on responsiveness and breathing, because feeling for a pulse is unreliable under stress, takes too long, and has led many people to think they felt one when there was none. Health care providers do add a pulse check, briefly, alongside the breathing check. For everyone else, the breathing is the question. the health care provider level that adds the brief pulse check.
A short jerking or twitching movement can also happen as the heart stops, and it is sometimes mistaken for a seizure. If the movement stops and the person is unresponsive and not breathing normally, the answer is the same. Go.
What if you are wrong?
People hold back because they are afraid of doing CPR on someone who does not need it. That fear is worth addressing directly. The 2025 guidelines state that the benefit of CPR for a person in cardiac arrest far outweighs the risk of compressions given to someone who is not. A person who is not in arrest will usually respond to chest compressions by moving, pushing you away, or groaning, at which point you stop and reassess.
The opposite mistake is the one that costs lives. Waiting for a person who is gasping to wake up, or for the ambulance to decide for you, spends the minutes that CPR and defibrillation need most.
When you call 911 in Alberta, the dispatcher will ask you about the breathing and help you make this call. Put the phone on speaker, describe what you see honestly, and follow their instructions. Current guidelines have dispatchers coach bystanders through hands-only CPR for adults, which is continuous compressions without breaths, so you do not need to remember everything on your own.
Reading about it is not the same as seeing it
Agonal breathing is hard to picture from a description, which is one reason hands-on practice matters: in a course you say the breathing check out loud on a manikin, again and again, until it becomes automatic. This post is not a substitute for that practice, and it does not certify you in anything. What it can do is plant one idea firmly enough that it comes back to you on the day: gasping is not breathing. the CPR-C course, where the breathing check is practised until it is automatic.
Quick answers
- What is agonal breathing?
- Agonal breathing is slow, irregular gasping that can happen for a short time after the heart stops. It moves little or no air and is not real breathing. It is common in the first minutes of cardiac arrest and is one of the main reasons bystanders delay CPR. Treat it as not breathing: call 911, start compressions and get a defibrillator.
- How long should I check for breathing?
- Five to ten seconds. You are looking for a regular, even rise and fall of the chest. Do not extend the check hoping to be certain. If you are unsure whether the breathing is normal, treat it as not normal and start CPR.
- Do I need to check for a pulse before starting CPR?
- Not as a bystander. Current guidance bases recognition of cardiac arrest on responsiveness and breathing, because pulse checks by lay rescuers are unreliable and slow. Health care providers add a brief pulse check as part of their training.
- Can CPR hurt someone who is not in cardiac arrest?
- The 2025 guidelines state that the benefit of CPR to a person in cardiac arrest far outweighs the risk to someone who is not. A person who is not in arrest will usually react to compressions, and you stop and reassess.
Sources
- American Heart Association: 2025 Adult Basic Life Support guideline: agonal breathing is present in up to 40% to 60% of out-of-hospital cardiac arrests, is a common reason lay rescuers do not recognise arrest, and the benefit of CPR far outweighs the risk to a person not in arrest. (checked 2026-09-23)
- Heart and Stroke Foundation of Canada: Canadian edition of the 2025 guideline highlights: the No-No-Go framework for recognising out-of-hospital cardiac arrest, and dispatchers guiding lay rescuers through Hands-Only CPR for adults. (checked 2026-09-23)
- Canadian Red Cross: First Aid and CPR manual: check for normal breathing for 5 to 10 seconds; occasional gasping is agonal respiration and the person should be cared for as if not breathing. (checked 2026-09-23)