We experience stress, or perceive things as threatening, when we think the demands being placed on us exceed our ability to cope.
A stressor is any event, experience, or stimulus that causes us stress. These events or experiences are perceived as threats or challenges and can be either physical or psychological. Stressors can make people more prone to both physical and psychological problems, including heart disease and anxiety.
We all know we have a limited short-term memory. If we try to memorise a long list of items, we can’t remember more than six or eight unless we use formal memory techniques. Similarly, although we have huge processing power in our brains, we can’t be conscious of more than a few thoughts at a time. In fact it’s fair to say we have a limited 'attentional capacity'.
As we become uncomfortably stressed, distractions, difficulties, anxieties and negative thinking begin to crowd our minds. These thoughts compete with performance of the task for our attentional capacity. Concentration suffers, and focus narrows as our brain becomes overloaded.
Our physiological response to stress involves high levels of sympathetic nervous system activation, often referred to as the 'fight or flight' response. This response involves:
- pupil dilation,
- release of endorphins,
- increased heart and respiration rates,
- slowing of digestive processes,
- secretion of adrenalin, and
- arteriole dilation.
This high level of arousal is often unnecessary to cope with micro-stressors and daily hassles, yet this is our body’s response, and it can lead to health issues.