ST. LOUIS - Thom Bick is the type of guy who has tattoos on his arms and chest, has permanent injuries from his time as a professional skateboarder, climbed a mountain on the way to his brother’s wedding, and goes caving because he is claustrophobic.

He admits he’s chasing a “natural high,” but isn’t sure he’d consider himself addicted to adrenaline.

“I don’t see it that way but I think other people would probably disagree with me,” he said. “To me it’s just out having fun.”

Psychologists say “adrenaline junkies” who enjoy or seek out risky activities actually just feel higher levels of dopamine after the sensational behavior than other people do—it’s more of a personality trait than an addiction.

While these people often enjoy extreme sports and activities, you also often find “higher sensation seekers” in dangerous jobs, like on the police force and in fire departments, according to Psychology Today.

But Brock Meece, a fellow “adrenaline junkie” and rep for Upper Limits Climbing Gym in St. Louis, says the behavior itself isn’t what thrills him – it’s overcoming a fear.

“It can be kind of empowering to eventually be able to say what once was a scary situation, I feel like I’m more in control of now.

The people who hang out at the gym say even they know getting hooked on adrenaline can be dangerous when you aren’t using all the precautions, or when you push past the limits of safety.

So whether it’s climbing, skateboarding, or bungee jumping, they say to make sure you’re learning from professionals or people you can trust, wear all necessary gear, and always have a partner to spot you.