You should give mouth-to-mouth breaths when someone has stopped breathing but the cause is likely related to a lack of oxygen rather than a sudden cardiac event. Drowning, opioid overdose, choking, and respiratory arrest in children are the clearest situations where breaths can make the difference between life and death. For a witnessed sudden collapse in an adult, where the heart itself is the problem, hands-only chest compressions are the priority, and mouth-to-mouth is not required.
The distinction matters because the underlying problem dictates what the body needs most. Knowing when to add breaths to chest compressions, and when compressions alone are enough, helps you respond faster and more effectively.
Hands-Only CPR vs. CPR With Breaths
The American Heart Association draws a clear line. If you see an adult suddenly collapse and you are untrained or uncomfortable giving breaths, start chest compressions immediately and keep going until help arrives. This is hands-only CPR, and it works well for sudden cardiac arrest because the person’s blood still contains oxygen for several minutes. Pushing hard and fast on the chest keeps that oxygenated blood circulating to the brain.
If you are trained and willing, providing breaths along with compressions is recommended for all adults in cardiac arrest. The 2025 AHA guidelines state that CPR with breaths may lead to improved outcomes compared with compression-only CPR. The standard pattern is 30 chest compressions followed by 2 breaths, repeated in cycles. You can deliver those breaths mouth-to-mouth, through a pocket mask, or with a face shield.
One important update from the 2025 guidelines: the AHA no longer uses the term “rescue breaths.” They now simply call them “breaths” when given during CPR or to someone who has a pulse but is not breathing.
Drowning: Breaths Come First
Drowning is the most important exception to the “start with compressions” rule. A drowning victim’s core problem is oxygen deprivation, not a heart rhythm failure. Their lungs need air before anything else will help. Current guidelines recommend giving 5 initial breaths before starting chest compressions, compared to the standard 2 breaths in regular CPR.
Trained rescuers can even begin mouth-to-nose breathing while still in the water, delivering about 12 to 16 breaths per minute for roughly one minute while moving the person toward safety. Once on dry land or in a boat, full CPR with compressions should begin. The Heimlich maneuver is no longer recommended for drowning victims.
Opioid Overdose: Breathing Is the Priority
Opioids kill by shutting down the brain’s automatic drive to breathe. The heart often keeps beating for minutes after breathing stops. This means the person may still have a pulse but is suffocating, making breaths the single most important intervention alongside naloxone (Narcan).
The technique is straightforward: pinch the person’s nostrils closed, seal your mouth over theirs, and deliver one breath every 5 seconds. If you have naloxone available, give it, but continue breaths between doses because naloxone can take a few minutes to work. If the person stops having a pulse, switch to full CPR with compressions and breaths.
The World Health Organization specifically recommends that first responders in suspected opioid overdose focus on airway management and assisted breathing alongside naloxone administration.
Choking That Leads to Unconsciousness
If someone who was choking becomes unconscious and you’ve lowered them to the ground, breaths are part of the protocol. Open the mouth, look for the object, and remove it if you can see it and it’s loose. Then tilt the head back, pinch the nose, and try giving two slow, full breaths. If the chest doesn’t rise, the airway is still blocked. Start chest compressions (30 at a time), check the mouth again for the object, then attempt two more breaths. Repeat this cycle until the object comes out or help arrives.
The compressions themselves can help dislodge what’s stuck. Once the object is out and the person is breathing, keep them still and wait for medical help.
Children and Infants
Breaths are more important for children than for adults. Kids are far more likely than adults to go into cardiac arrest because of a breathing problem (choking, asthma, near-drowning) rather than a heart rhythm issue. Their smaller bodies burn through available oxygen faster.
Large studies of children who experienced cardiac arrest outside a hospital found better outcomes with CPR that included breaths, whether at a ratio of 15 compressions to 2 breaths or 30 compressions to 2 breaths, compared with compression-only CPR. If you find an unresponsive child or infant who isn’t breathing, giving breaths is strongly recommended.
When Someone Has a Pulse but Isn’t Breathing
This situation, called respiratory arrest, is different from cardiac arrest. The heart is still working, so chest compressions aren’t needed. What the person needs is air. Tilt the head back, lift the chin, pinch the nose, and deliver a breath every 5 to 6 seconds (about 10 to 12 breaths per minute). Check for a pulse roughly every 2 minutes to make sure the heart is still beating. If the pulse disappears, begin full CPR.
Respiratory arrest can happen from opioid overdose, severe allergic reactions, near-drowning, or seizures. The visible sign is simple: the chest is not rising and falling.
Don’t Mistake Gasping for Breathing
One of the most common and dangerous mistakes bystanders make is hearing gasps and assuming the person is breathing. Gasping, sometimes described as snoring, gurgling, moaning, or snorting, is a sign of cardiac arrest, not a sign that everything is fine. A person who is gasping needs chest compressions immediately.
Gasping actually indicates the brain is still alive, and starting compressions quickly gives that person a strong chance of survival. Researchers at the University of Arizona’s Sarver Heart Center note that mouth-to-mouth breathing during gasping can actually be counterproductive: the gasps create a natural suction that pulls blood back into the heart, while blowing air in creates pressure that inhibits that blood flow. For a gasping adult who has collapsed, uninterrupted chest compressions are what they need.
Choking looks entirely different. Someone who is choking will be conscious, grasping at their throat, and visibly struggling. That’s a responsive person with an airway problem, not someone in cardiac arrest.
When to Stop
Keep giving breaths (with or without compressions, depending on the situation) until one of these things happens: the person starts breathing on their own, emergency medical services take over, you become physically exhausted and cannot continue, or the scene becomes unsafe. If you’re performing full CPR and there has been no response after 20 minutes of continuous effort, with no signs of the heart restarting, that is generally considered the point at which further resuscitation is unlikely to succeed.