Think you can beat the current world record? Before you try, here's what happens when you hold your breath.
This Is What Happens To Your Body When You Hold Your Breath
Updated on Jun. 27, 2025
From childhood contests to grown-up moments of poolside bravado, most of us have tested our limits to see how long we can go without breathing. The aftermath includes experiencing a little breathlessness, maybe some lightheadedness too, but nothing too serious. Right? Not quite. What happens when you hold your breath goes far beyond that quick dizzy spell. From plummeting oxygen levels to unexpected effects on your brain and body, there’s a lot going on when you hold your breath.
Science says there’s only so long we can go without a good gulp of air, and it depends on things like age, fitness and lung power. Sure, some people take it to the extreme. (We’re looking at you, Budimir Šobat, who held his breath for a wild 24 minutes and 37.36 seconds!) But even with record-breaking training, your body still feels the impact. Curious about what happens when you hold your breath? Read on as we take a deep dive into the surprising science behind it.
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Is it safe to hold your breath?
It depends. Most of us have tried breath-holding, whether at yoga class or while swimming laps, but it’s only safe when it’s done with proper technique and training.
Competitors and professional divers train rigorously over extended periods of time. (It turns out that holding one’s breath at length—also known as voluntary apnea—is somewhat of an extreme sport in and of itself.) By taking deep breaths before submerging themselves, and also performing various other fitness exercises, a diver is able to push the carbon dioxide out of his or her body, which takes away the body’s natural reaction to come up for air.
But even with all the training in the world, how long is it actually safe to do so? We’ve got the answer for you ahead.
How long can humans hold their breath?
Unlike loggerhead sea turtles, who can go without air for up to 10 hours (the longest in the world, by the way), most healthy human adults can comfortably hold their breath for 30 to 90 seconds, according to Medical News Today.
Anything beyond this is dangerous and should be avoided, as it can put you at risk for drowning—even in shallow water. But that’s not the only risk. Coming up: What’s going on within in your body when you hold your breath.
What happens when you hold your breath?
By now, we know there’s only so long the human body can go without air. And whether you’re trained or not, pushing past that limit sets off a chain reaction in your body as it copes with the lack of oxygen. Here’s exactly what happens when you hold your breath for too long:
Oxygen levels drop
Without fresh oxygen coming into our bodies, the oxygen saturation level of our blood goes down. This means that our brain and organs do not receive the oxygen they need to function, a condition called hypoxia. When our brains begin to become hypoxic, the first symptoms are a feeling of confusion, altered decision-making and loss of coordination.
Carbon dioxide levels rises
Our bodies release carbon dioxide (CO2) when we exhale, so when we hold our breath, CO2 builds up and we get the urge to take another breath. However, this increase in carbon dioxide doesn’t always happen underwater.
A study in the European Journal of Applied Physiology found that when divers intentionally hyperventilate or exercise before going underwater, their carbon dioxide levels are slower to go up. This can put the diver at risk of passing out before feeling the need to come up for air.
Risk of brain damage goes up
A study in the Journal of Applied Physiology found that when divers held their breath for extended periods of time, they had higher levels of the protein S100B in their bloodstream. This protein is a marker for brain damage; fortunately, the increased level was temporary and went back to normal once they started breathing again.
“The results indicate that prolonged, voluntary apnea affects the integrity of the central nervous system and may have cumulative effects,” explained the researchers. It’s still unclear whether people who regularly hold their breath—like divers—face long-term risks, but the short-term effects are well documented.
Coordination is affected
That same study in the Journal of Applied Physiology also found that divers had higher levels of lactate (an ionized form of lactic acid) in their blood while holding their breath. Lactic acid is what builds up in your muscles during a long run or intense workout, and it can lead to cramping, soreness and loss of coordination. An increase of lactate in the bloodstream means that the muscles are not receiving enough oxygen.
Blood sugar levels rise
Holding your breath for too long can cause your blood sugar to jump. In the same study, researchers also found that blood glucose levels were higher in divers when holding their breath. It’s unclear why blood sugar rises when the body is deprived of oxygen, but it may be related to our body’s inability to secrete insulin during that time.
Heart rate slows down
When our bodies are deprived of oxygen, the heart can’t pump fresh, oxygenated blood out to the body. Studies show that about 30 seconds of breath-holding can lead to a lowered heart rate and lower cardiac output.
Blood pressure goes up
Once your body’s heart rate goes down during breath-holding, it tries to compensate by raising your blood pressure to get blood pumped to the body. It happens as our blood vessels constrict. This blood pressure increase usually begins after three minutes of breath-holding, once the oxygen level in our blood starts dropping.
Risk of passing out increases
The most dangerous risk of holding your breath underwater is the possibility of passing out in the water. When children hold their breath underwater, the pressure in their chests causes their blood vessels to cut off blood flow to the right side of the heart. As this happens, the heart can’t pump blood, which leads to the fainting reflex. Adults who hold their breath for extended periods underwater are also at risk of passing out.
So, should you hold your breath for extended periods of time?
Because of the very real risks involved—including accidental drownings among healthy kids and adults—the Centers for Disease Control and Prevention advises against practicing voluntary apnea altogether. So yes, breath-holding games are a no-go.
But if you’ve got dreams about going toe-to-toe with Budimir Å obat’s jaw-dropping world record, it’s best to train with professionals under strict medical supervision. Safety first, bragging rights later!
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Sources:
- NBC News: “Don’t Hold Your Breath: CDC Reports on Pool Accidents”
- Guinness World Records: “Longest time breath held voluntarily underwater (male)”
- Medical News Today: “How long can the average person hold their breath?”
- National Library of Medicine: “Cerebral hypoxia”
- European Journal of Applied Physiology: “Aggravated hypoxia during breath-holds after prolonged exercise”
- Journal of Applied Physiology: “Increased serum levels of the brain damage marker S100B after apnea in trained breath-hold divers: a study including respiratory and cardiovascular observations”
- Centers for Disease Control and Prevention: “Fatal and Nonfatal Drowning Outcomes Related to Dangerous Underwater Breath-Holding Behaviors — New York State, 1988–2011”
