吃飽太空閒之My attempt to understand the science behind "Stress"

A casual conversation with a friend stirred up my interest to read up on yet another random topic through google search.

Well it isn't that random aye? University students say they are under 'pressure' to keep up with their lecture materials; working adults say they are constantly rushing for deadlines; even full-time mothers complain about how 'stressful' it is to take care of young children, send them to school and return home only be greeted by housework that never seem to end.

I hated Biology in high school, that's why I didn't take up my dad's suggestion to pursue a medical degree. Yet, I surprised myself by my renewed interest in reading stuff about Biology, though I suspect the main reason being its relevance to me (and so many other university students).

It seems strange to me at first how stress can kill. It is untouchable, and its existence is sometimes difficult to define. Unlike a bullet which can go through a person's head and condemn him/her to instant death, stress does not have any physical sense of existence, yet depression is the number 1 cause of 'disability' in the population of Victoria.

My amateurish attempt at understanding some medical journals I found online led to a simplistic explanation. What we termed as 'stress' is actually a natural reaction to "dangerous" or "potentially life-threatening" situations, in the context of simple animal survival. Such reaction isn't supposed to be prolonged ie animals either escape from danger or die, in either case the body response to heightened level of anxiety will not last for a long time.

However, human extended existence beyond what nature lays down for us as well as our sophisticated brain structure which makes us 'aware' of our environment make us, I believe, more prone to stress than the wild animals whose only concern is 'survival'. Human invented responsibilities, commitments, love, care, duty - all contribute to different, and in some ways, more intense, level of 'stress' compared with the natural sources which are limited to predators, change in living environment and climate.

My poor grasp of Biology terms did not allow me to comprehend exactly the workings of our body's response to stress. I believe it is some sort of hormonal reaction, in that under stressful situations our body release some hormones to help us cope with the 'external danger'; however if the level of such hormones stays high for too long our immune system will start to deteriorate and this makes us more prone to illnesses.

So it is like alcohol. If it stays in your blood stream ALL THE TIME, you die of toxic.
It is akin to AIDS, which weakens your immunity and let other viruses kill you.
It is like some cancer. You can only try to manage it but not get rid of it completely.