The ancient Greeks used to say that ‘Παν μέτρον άριστον’, which roughly translates to ‘moderation in all things’. Stress is in no way an exception to this rule. If anything, it’s one of the finest examples for it.
Stress comes in different forms depending on the individual, because not everyone finds the same things to be stressful or even to be stressful to the same degree. To some of us, the prospect of giving a presentation in front of an audience will give us stage fright hours or even days before even setting foot on the stage, while for others it will simply mean a brief moment of nervousness right before starting the presentation.
Imagine that you are in a waiting room, fifteen minutes away from being called in for your interview with a potential future employer. You’re looking at the clock on the wall and with every passing second your heart beats a little bit faster. At that moment, your autonomic nervous system triggers the ‘fight or flight’ response and releases hormones, mainly adrenaline and cortisol. Adrenaline has a stimulating effect, increasing your heart and breathing rate, dilating your blood vessels and sharpening your senses, as well as bringing your brain to a higher state of alertness. On the other hand, cortisol aims to re-establish homeostasis within your body (i.e. to bring back a chemical and physiological balance) in response to the stressful situation, through a wide range of metabolic activities, one of them being the temporary downregulation of the immune system and especially the inflammatory process.
In such an instance, transient stress can be considered beneficial, since it heightens your awareness and thus allows you to deal with the increased demands made upon you by the job interview.
Now imagine that you are waiting for that same interview, only instead of fifteen minutes, it’s fifteen days before the interview and you are at home doing your research as for what to expect during the process. As you realise that the date of the interview is approaching, you feel a knot in your stomach that won’t go away for the next fifteen days. Even though the ‘threat’ posed by the interview is days away, your body is unable to make this distinction, and reacts by continuously activating the ‘fight or flight’ response. During this time, you are constantly producing adrenaline and cortisol, with the latter having a detrimental effect on your health by keeping the immune system working at a below optimum level, hence lowering your defences against infection by pathogens.
In contrast with the first situation where brief stress gave you a bit of an edge for your interview, in this case chronic stress weakened your immune system and exposed you to a whole host of diseases.
Therefore, it seems wise for all of us to take the advice of the ancient Greeks and try to keep stress, as well as other things in our lives, at moderate levels (which is paradoxically a sort of stressful thing to do).