During an adrenaline rush, the body shifts into high gear and creates a feeling of heightened awareness. This term is also referred to as a fight-or-flight response or adrenaline release, and it occurs in response to a situation that is dangerous or thought to be dangerous. When an adrenaline rush is triggered, the body releases adrenaline into the blood to gear up for a fight or to prepare to run from the threat.
Adrenaline, also known as epinephrine, is a hormone that occurs naturally in the body. This substance triggers specific physical reactions when production increases. An adrenaline rush originates in the sympathetic nervous system as a response to stimuli or specific stressors. Fight-or-flight triggers can include physical threats, confrontations, loud noises, bright lights, excitement, and excessively high temperatures.
An adrenaline boost causes a number of physical symptoms, including rapid pulse and breathing, all designed to urge the body into action. The term flight-or-flight response is used to describe an adrenaline release, because it addresses the body’s reaction to the increase in hormone production. When presented with some type of real or perceived danger, the body reacts physically to find safety or protection.
Someone experiencing an adrenaline rush feels as if every nerve is on alert. The heart races and breathing increases to pump more blood into the muscles, allowing them to work more efficiently. Pupils dilate so vision becomes clearer, even if the surrounding area is dark. Hair stands on end and the entire body experiences a higher level of sensitivity. Sweat glands open to help cool the now active body, which can lead to a clammy appearance.
Blood flow to the muscles increases during adrenaline rushes, but vessels in the skin constrict to prevent excessive blood loss from injury. Bodily functions such as digestion come to a standstill, but the liver immediately goes into metabolic action, creating an instant energy boost. Cases have been reported when an adrenaline rush produces seemingly superhuman strength, enabling a person to lift a car or carry someone long distances in response to a life-threatening situation.
Real or perceived threats can trigger an adrenaline rush. Anxiety or panic attacks may be caused by a boost of epinephrine released into the bloodstream in response to an imagined stressor. The fact that there is no real danger does not prevent the fight-or-flight response. Any stressful situation that gives the perception of danger can lead to an adrenaline release.
Daredevils and extreme athletes are sometimes called adrenaline junkies, because they seek out the feeling caused by an adrenaline rush. Dangerous or exhilarating activities are known to cause the release of epinephrine, and these so-called junkies participate in these actions just for the rush. Extreme sports such as BASE jumping and skydiving can produce an adrenaline rush.