Are you an adrenaline junkie? Here's what it really means.

It you know someone who likes to skydive, free solo rock climb, or does motocross, chances are you know an adrenaline junkie.

Once thought to be a "high" chased only in extreme sports like base jumping, the chemical releases associated with ramping up the risk of more accessible sports can be just as alluring. This occurs when a safer activity like rock climbing is deliberately made less safe by doing so without the added security of a rappel rope (free soloing), or when a downhill mountain biker decides to let go of their handlebars while going over a jump in order to make the stunt more dangerous and therefore more thrilling.

Emily Hemendinger, the clinical director of the Intensive Outpatient Program at the University of Colorado Anschutz Medical Campus, says some telltale signs of being a so-called adrenaline junkie include regularly engaging in activities that may be dangerous or unhealthy "for the rush of it," or experiencing an intense and persistent need to participate in such activities. These individuals "can also be impulsive, spontaneous, and frequent seekers of new thrills and experiences," she adds.

What is an adrenaline junkie?

While many people refer to extreme sports athletes as adrenaline junkies, mental health professionals refer to them as "thrill seekers" or "high sensation seekers." The latter is a term coined by the late psychologist Marvin Zuckerman, who taught that such people like to "pursue intense sensations and experiences and are willing to take big risks for those experiences," explains Kenneth Carter, a professor of psychology at Oxford College of Emory University and the author of "Buzz! Inside the Minds of Thrill-Seekers, Daredevils, and Adrenaline Junkies."

Such individuals may participate in activities like mountaineering, ice climbing, white water rafting, big wave surfing, highlining, bungee jumping, downhill mountain biking, stunt biking and extreme skateboarding. "Really any risky or dangerous behavior that causes intense sensations and a 'rush' can trigger the emotional response thrill seekers are seeking," says Marc Dingman, a biobehavioral health scientist at The Pennsylvania State University.

Adrenaline junkies are often introduced to risky and thrilling sports and activities by a friend, family member or work colleague, then finding that they enjoy the feelings associated with doing them. "Thrill seekers may also be more genetically predisposed to have underlying psychiatric disorders, higher levels of impulsivity, and lower tolerances to boredom," says Hemendinger. "And they may be more likely to be impatient, self-preoccupied, and have difficulty accepting and dealing with failure."

What 'high' are adrenaline junkies seeking?

No matter what's behind one's desire to engage in extreme sports or activities, the experienced effects are often the same across each one. "There’s a lot that goes on in the body when we do something thrilling or dangerous," says Carter. He explains that some common responses include the release of hormones such as cortisol - "which helps to organize our body's fight-or-flight response;" and dopamine - "a neurotransmitter that causes feelings of pleasure."

One's heart usually beats faster as well, digestion slows ("which might explain butterflies in your stomach," Carter says), pupils dilate, reflexes quicken, lungs expand to allow increased airflow, and muscles flex and tighten. Some of these responses are activated by the release of two additional hormones and neurotransmitters: adrenaline and noradrenaline - "which help to promote these physiological changes," says Dingman.

Are extreme sports actually addictive?

Because higher levels of hormones are released when engaging in dangerous activities, some people think extreme sports are addictive, hence the term adrenaline "junkie." The reality is a bit more complicated.

While dangerous sports or activities are likely nowhere near as addictive or hard to stop doing as drugs or alcohol, says Holly Blake, a professor of behavioral medicine in the School of Health Sciences at the University of Nottingham, "some research does suggest that some extreme sport athletes can experience withdrawal symptoms during abstinence from their sport and these withdrawal symptoms can be similar to those experienced by individuals with substance and behavioral addictions."

Such symptoms and desires can be multiplied the more the extreme activity is done. "Just like with drugs and alcohol, the more you do something that is addictive, the more tolerance you build and the more of it you have to do in order to experience the 'high' again," says Hemendinger.

Indicators that an extreme sport or activity is becoming addictive are similar to addiction to substances or compulsive behaviors like gambling, she explains. "Signs to look out for include disregarding the potential risks of the activity, lying to yourself or others about the dangers associated with the activity, rigidity around doing the activity including getting upset when not able to do it, or the activity interfering with your relationships and/or work or school responsibilities," she says.

Is it OK to be an adrenaline junkie?

Keeping an eye out for such signs or symptoms can be helpful when determining if rarely participating in a dangerous sport or activity has become a problem that's increasingly likely to cause injury or harm. "The more you engage in risky activities, the more likely you are to become hurt," says Carter.

To avoid the worst outcomes of participating in extreme sports or activities, Hemendinger says it can be helpful to limit frequency, to avoid pushing safety boundaries, to wear protective equipment, and to listen to your gut if a stunt or action seems like it could lead to serious injury or death if any number of uncontrollable factors goes awry. "And trust your friends and family if they are asking you to cut back on some of your adventurous activities," adds Carter. "They may see danger in places you don’t."

This article originally appeared on USA TODAY: What is an adrenaline junkie?