What is adrenaline
Adrenaline or epinephrine is a hormone produced by adrenal glands (glands that are located on top of kidneys). Adrenaline pushes our body into overdrive mode - our heart races, our blood pressure jumps, we receive an enormous boost of strength. Our awareness rises, our reflexes improve. This is a natural adaptation of many species to a sudden dangerous or near-death situation, where the organism is required either to fight for its life or to run for its life, which is known as fight-or-flight situation. Once the situation that caused this adrenaline rush resolves, no more adrenaline will be pumped form the adrenal glands, and what is left of it in circulation will be absorbed and removed from the system.
What are adrenaline junkies
To most people, adrenaline rush has similar effect as drugs, and causes a great sense of satisfaction. To some people, however, this sensation of being "naturally high" is so good that they effectively become addicted to adrenaline. But, instead of sniffing, smoking, licking or injecting it, they use their own body's natural response to danger to get a free fix. Such people are commonly referred to as adrenaline junkies.
What do they do
First thing that comes to mind when we think of adrenaline junkies are extreme sports. These are sports such as bungee jumping, skydiving, base jumping, stunt bicycle riding and skateboarding, high speed motor sports, and any others that include elevated or high risk of injury or death. These are all situations in which our body realizes that it is in a high risk situation and constantly releases adrenaline.
There are also high risk professions, which frequently expose those who pursue it to dangerous situations. Think of police officers, firefighters, soldiers, ice truckers, and crab fishermen. They all face dangerous situations and put their life on the line. Being shot at by an enemy fighter or desperate mobster, fighting your way to a blazing building, riding a truck over the ocean or being pounded by a house-tall icy waves - all these are situations that trigger adrenaline secretion. Of course, not all of those people are adrenaline junkies, but it is likely that some of them choose their profession because it is "thrilling".
Like all other addicts, adrenaline junkies tend to be low if they don't get their fix regularly. Unfortunately, this means that they will put their life on the line often, too often for most of their families and friends or loved ones. Some of adrenaline junkies are even prone to start a meaningless argue or fight just to trigger an adrenaline rush. This is a lifestyle that frequently burns them out too soon, and one that is very hard to cope with.