What is the stress response?

Physiologically, stress is part of our body's hardwired protection system. When we perceive a situation as stressful, we are essentially perceiving it as a type of threat that requires us to increase our physical resourcefulness to enhance our survival. From an evolutionary viewpoint, this meant that we were prepared to attack or escape predators. Our nervous system jumps into action, known as the acute stress response.

HOME

Activation of the stress response

When the acute stress response is activated, we are flooded with chemicals, like adrenaline and cortisol, that give us a boost in mental alertness and physical performance. Our vision

sharpens and our thoughts start racing, so we can better see and evaluate danger. Our bodies tense up. Our heart and breathing rates increase so blood and oxygen is sent quickly to power our muscles. Our hands get cold and clammy as blood vessels constrict to force blood towards major muscle groups, and our body sweats so it can run cool and efficiently. We can feel nauseas or like

we have butterflies in our stomach, as blood is also diverted away from the digestive system towards, you guessed it, our muscles.

TiredEachBoaconstrictor-size_restricted.

This process is clearly helpful when we need it for an immediate stressor, like a bear in front of us, but it becomes problematic when it is activated and we don’t really need that physiological support for what we are dealing with. I don’t need to be flooded with adrenaline and have my muscles tense and my vision sharpen when I am late and stuck in traffic. Or when I am nervous for a job interview. Those chemicals are just going to be coursing through my body with no real output.

FOLLOW

Sustained stress

The real problem with the stress response is that it is highly receptive and has not adapted to the

normal stress that is part of modern life. Now anything that is perceived as a demand/threat

activates this response, including minor inconveniences. Just thinking about a bear, or an assignment, or our mortgage can activate the response.

It is problematic when this system is chronically activated, whether due to us regularly stressing out over traffic on a daily basis, or from numerous new or ongoing stressors. This underlying physiology in sustained stress causes those disruptive stress symptoms:

This response uses a lot of energy and as a result we feel fatigued and lethargic.
Energy is also saved and redirected towards dealing with the stressor, and our body's immunity, growth, and repair process is postponed. This means susceptibility to colds, a longer time to heal from an illness or a wound, and even difficulty with reproduction/fertility. Chronic activation also increases risk of hypertension and metabolic issues that contribute to diabetes and other diseases.
Constant tensing of our muscles leads to aches and pains.
Adrenaline pumping through our body cause us to have difficulty "winding down." We can have trouble falling asleep.
Our brain becomes preoccupied with the stressor, so it is harder for us to focus on something else. This increased "cognitive load" also makes it difficult for our prefrontal cortex (involved in complex cognitive tasks and moderating behaviour) to help us make good decisions. We can run on autopilot, which may mean engaging in behaviours that are more about immediate comfort (i.e., comfort eating or substance use) than what is best for us.
Our amygdala is highly activated during times of stress. It is involved in both the processing of fear and emotional regulation. As a result, we may be more emotional than usual when we are stressed. The activation of the amygdala, coupled with high cognitive load impacting our prefrontal cortex, can cause irritability and aggressive behaviour (i.e., snapping at others over little things).

CONTACT

Not all stress is bad. Stress is normal in our lives and we need what’s known as eustress to perceive some amounts of pressure to be activated, alert, and motivated to prepare for and write a test, engage in competition, or to drive carefully. This is when a surge in adrenaline and focused thoughts is helpful. Some stressors are even from positive events, like getting married, having a baby, or the holiday season. Stress management is really about strategies for managing stress when it becomes problematic, when the stress response is getting in the way of dealing with the stressor and/or is a result of sustained stress. We need to be able to lessen its impact. A basic approach to stress management is introduced in Different Ways to Deal With Stress.