Even though you realise that there is no reason for alarm your body continues to respond as if facing an urgent and immediate threat to survival. It doesn’t help to tell yourself to calm down and keep cool. Indeed because such instructions have no chance of being obeyed, what usually happens is increased anxiety as you realise that your feelings are out of control.
The changes which have been brought about by the ANS, increased heart rate, rapid breathing, more sweating and so on, can only be corrected and the body returned to normal running by the same mechanism which speeded them up in the first place, that is the autonomic nervous system.
This is possible because the ANS has two branches which, most of the time, work in harmony to create a state of normal arousal. The two branches of the ANS may be compared to the reins of a horse. To keep the animal moving forward in a straight line, the rider applies equal pressure to each side. If more tension is applied to either rein, however, the horse will turn in that direction.
In the ANS these reins consist of two mechanisms. One, which increases arousal, is known technically as the sympathetic branch while the second, which slows the system down again, is called the parasympathetic branch.
As you sit at home watching TV and feeling relaxed and stress free, the slow-down, or parasympathetic, branch is exerting dominance over the system. As a result your heart rate is moderate and breathing slow.
When life gets more stressful, however, the speed-up, or sympathetic, branch gains the upper hand, raising heart rate, increasing breathing, sweating and muscular tension.
To bring about these bodily changes the ANS relies on chemical messengers, hormones, to carry its instructions to all parts of the body.
The best known of these hormones, adrenalin, has been dubbed ‘jungle juice’, since it plays such a vital role in the fight-and-flight response. That sharp sensation of discomfort in the pit of your stomach which signals a rise in anxiety is produced by the sudden release of adrenalin.