Here's what can happen to your brain and body when you shoot a gun

Firing a gun can overwhelm our brains with the fight-or-flight response. But for some people, the experience feels rewarding.

  • Shooting guns can trigger a fight-or-flight response, especially in novices.
  • This makes the heart race, palms sweat, and sometimes even leads to nausea.
  • However, feel-good chemicals can also flood the brains of thrill seekers and marksmen.

You look down the sight of a gun, take aim, slowly exhale, and pull the trigger.

What happens next is an explosion of sensations, from a bright muzzle flash and body-jolting recoil to an ear-splitting bang and acrid smell of burnt gunpowder.

About 72% of US adults have fired a gun, according to a June 2017 Pew Research Center survey that reached nearly 4,000 respondents. This means most of America is familiar with the experience — including the mental and emotional head-rush that often comes with it.


"The whole idea of training is to get people over these sensations, whether they're a police officer-in-training or military personnel," Kevin Fleming, a neuroscientist at Norwich University (a military college) who's researched gun violence and the psychology of shooting firearms for more than 25 years, told Business Insider.

Although everyone's experience is different — especially when it comes to a firing range versus a real-life threat (perceived or otherwise) — here are a few effects that shooting a firearm can have on the brain and body.

Firing a gun can be startling. In response, first-timers can experience a fight-or-flight response — the body's way of automatically responding to what it perceives could be mortal danger.

The brain rapidly releases cortisol, adrenaline (aka epinephrine), and other hormones like serotonin, dopamine, and norepinephrine. This can lead novice shooters to feel intense fear, anxiety, or aggression after shooting.


"In order to pull that trigger, you're standing your ground, and you're going to use this weapon to help you. There is that 'fight' part of it," Fleming said. "I know it's just a paper target, but some people are seeing that as the enemy. ... Pulling the trigger is an act of aggression."

Just seeing a gun can prime aggressive thoughts, according to one recent study, and even experienced shooters have to manage their body's responses after firing thousands of rounds in countless training scenarios.

"The training is primarily designed to ... bypass all of the emotional baggage of the experience," Fleming said. "But I don't think it ever fully goes away."

The fight-or-flight response evolved to keep us alive in sticky situations, and spiking hormone levels also triggers a grab-bag of autonomic (i.e. uncontrollable) bodily reactions.


"It's based on our primate heritage," Fleming said. "If you're going to run away from or fight something, you'd better start breathing faster to get enough oxygen in your blood, and pumping that oxygen around."

As a result, the heart begins to race, blood vessels constrict, and blood pressure skyrockets, in turn rapidly delivering oxygen and sugar to muscles.

The rush of blood and fight-or-flight levels of neurochemicals also affects the brain's function.

Mental focus increases, and so does the ability to recognize patterns, while time seems to slow down (though it doesn't actually do so) with an increased flow of conscious and subconscious information.


"The sweaty palm helps you get a better grip," Fleming said, and wider-open eyes help you see more of your surroundings, especially in the dark.

The body may also stop processing food.

"You can get sick to your stomach if you've have a big meal," Fleming said. Though it's rare, he added, "you might even get diarrhea. If you're an animal, you are not going to carry that extra weight if they don't have to. The same thing with urine."


All of these responses happen more or less at once, Fleming said, and often before the brain has consciously processed that a gun has fired.

After the danger has passed, the nervous system responds by releasing all sorts of chemicals to calm the body back to normal, while others that spiked linger for some time.

The initial response and come-down that follows can lead to a strong sense of pleasure in some people.

"That rush of serotonin feels good," Fleming said. "A lot of people don't like being scared, but there are people who like to jump out of airplanes or bungee jump."


Knowing that you've exercised enough skill to hit a target precisely where you aimed can also be a powerful and rewarding sensation.

However, Fleming noted that most professional shooters he's met — primarily police officers and military personnel — aren't adrenaline junkies and espouse a "healthy respect for guns."

"There may be some people who get a thrill out of going to the range," he said. "But most professionals I've met are not that interested. They don't want to bring that home at the end of the day."


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