As most people know, stress first showed up in our bodies as a pretty potent way of keeping alive. Back in the day, if you were staring down a saber toothed tiger, your fight or flight response (triggered by the stressful encounter) kept you alive. Either you stood and fought the tiger, or you turned tail and ran away as fast as you could. Which ever action you chose, to stand your ground or to turn on your heel, was aided by your body's stress reaction.

When encountering something life threatening, your body would undergo some important changes. Your body would start pumping up your adrenaline causing a number of helpful changes. Your heart rate and blood pressure would shoot up. Your breathing would increase and your nostrils would flare to let in more oxygen. Your digestion and other momentarily non-essential bodily functions would slow way down. Blood would leave your skin and your internal organs, and instead flush into your brain and skeletal muscular system. Your blood clotting response would shoot way up. Your vision would improve as your pupils dilated to let in more air. And finally your liver would start processing your blood sugar, providing you with the quick burst of energy you would need to survive.

While all of this is great and helpful when staring down a hungry and dangerous mega-fauna back in the stone age, we don't exactly face large sharp fangs on a daily basis anymore. Yet, despite the decrease in large threats to our existence, our extremely helpful and functional fight or flight system still sits buried within our reptilian brains. And while there are still moments in the modern world where this response can be helpful (bar fights, running into sketchy strangers in long dark alleys, or when you need to jump out of the way of a barreling cyclist) you generally aren't going to run into too many instances where this response is needed.

But, unfortunately, your body isn't always the best at perceiving when a stressor is life threatening, or merely annoying. Maybe it's because we simply blow up little stresses way out of proportion, but it seems like our bodies kick in with the fight or flight response whenever we face anything that causes stress, regardless of whether or not the obstacle is as life threatening as a saber toothed tiger. So even though most of our stresses these days are psychological or social, our bodies still kick in as if we're being chased through the jungle.

After all, what's most people's biggest fear? It's not death anymore, it's public speaking. For most people, when they get behind a podium in front of some people (whether a dozen or a thousand) their fight or flight response kicks in. Maybe they're worried about the social ramifications of messing up behind the podium, or maybe they're concerned about what this may or may not do for their career. Most people will start to feel queasy, nervous, sweaty, anxious- in a word, stressed. Even though you probably won't die up there, you feel like you might.

So while we rarely face life threatening situations these days, it's hard to tell that to our sympathetic nervous systems.