Understanding Stress

In our society we take stress as a given and don’t pay much attention to the effects it has, except possibly when we go to the doctor with high blood pressure and he or she says you’re probably under too much stress. 

But stress plays a much more significant role in our lives than whether your blood pressure is high or not.  Among other things stress can effect the functioning of your cognitive functioning, including memory.

It’s your emotional make-up that determines if you perceive any set of circumstances or events, as stressful and, if so, how stressful.  In essence, you create your own stress.

Your brain perceives all stress as a threat, or potential threat, to its survival.  Threat disturbs your brain’s sense of comfort.  Comfort means safety and safety means survival.  Your brain wants to survive in a state of comfort. 

But there are all kinds of things in our daily lives that can disturb your brain’s comfort.  The question is, “To what extent and for how long will it last?”  The answer to those questions will determine the damage, if any, produced by your brain’s stress response.

When your emotions warn your brain of an impending threat your brain responds by releasing a  series of defensive hormones; adrenaline, norepinephrine (noradrenaline) and cortisol.

Sugar, which is converted to glucose in your blood, is your system’s primary source of energy.  Normally, your brain uses insulin to keep the sugar in your blood balanced at a desirable level.   But during periods of stress your insulin response is held back.  Your brain causes adrenaline, a sugar substitute, to be released into your blood raising sugar levels. The added sugar, provided by the adrenaline, is used to fight off, or flee from, the stressor.

The primary task of Norepinephrine is to mobilize the brain and body for action. In doing so, it increases arousal, alertness, vigilance, retrieval of relevant, stored information and focuses attention. It increases heart rate, blood flow and blood pressure. If adrenaline can’t provide enough sugar, Norepinephrine will attempt to convert fatty tissue in the body to sugar. Norepinephrine performs a lot of its work by diverting blood, along with its energy stores, from areas not needed, to those needed to fight, or flee, from the stressor. 

Then there’s Cortisol. Cortisol is the brain’s traffic cop during periods of stress. Cortisol holds systems back so that Norepinephrine and Adrenaline can do their job, which is to defeat, ward off, or escape from the stressor.

During this time Cortisol is helping Norepinephrine reroute blood and hold back functioning elements of the brain not considered useful in defeating the stressor. That includes the hippocampus a primary source of experience-dependent brain cells essential for memory and learning and the production of dopamine, a neurotransmitter, also essential for memory and learning.

There’s only one problem with this well thought out system.  It’s intended to have limited time requirements.  Accordingly Adrenaline and Norepinephrine have a limited life span.  But your brain will continue to introduce Cortisol into your blood as long as it feels that the stressor is still present.

When Cortisol is the only stress hormone remaining in your blood it becomes toxic attacking and damaging neurons, tissue and cells at random.  It also continues to reroute blood and hold back functioning elements of the brain not considered useful in defeating the stressor.  That includes the elements of the brain essential for memory and learning.

There are three types of stress; acute, or short term stress, chronic stress and oxidative stress.

Acute (short term) Stress

Acute stress results from specific events or situations that involve change, are  unpredictable, pose a threat to the ego, or are involved with achievement while  management of the situation is beyond the control of the individual .  Acute or short term stress can be good for you because the stress hormones released help your mind and body to focus on the stressor and expand your ability to deal with similar stressful circumstances.

Chronic (long term) Stress

 Chronic stress results from repeated, or continued, exposure to situations that are continually changing, are unpridictable, emotionally demanding, pose a continuing threat to the ego but the individual is unable to bring the situation toward termination.

During periods of chronic stress the stress hormones Adrenaline and Norepinephrine are depleted.  Cortisol is left alone to fight the stressor.  When Cortisol is the only stress hormone remaining in your blood it becomes toxic attacking and damaging neurons, tissue and interfering with cell function, all at random.  Cortisol will also continue to reroute blood and hold back functioning elements of the brain not considered useful in defeating the stressor.  That includes the hippocampus, the element of the brain essential for memory and learning.  Chronic stress can also reduce the production of Serotonin, the feel good hormone.

The hippocampus produces the experience-dependent brain cells needed to absorb new information, make new memories and learn.  The hippocampus produces the neurotransmitter dopamine which is needed to transmit and retrieve stored  information.

When stress is chronic your brain is not producing the experience-dependent brain cells or the neurotransmitter needed for memory and learning.  Since  chronic stress can reduce the production of Serotonin, the feel good hormone, it can also lead to depression.

Your first thought in dealing with chronic stress is to ask yourself if you can withdraw mentally from the situation by becoming an objective observer of what’s taking place.  If you can’t do that you have to ask yourself whether you can remove yourself physically and mentally (flee) from the situation. If the source of the chronic stress comes from a close personal relationship, your job, or because you’re a caregiver and can’t withdraw from the situation there are other things you can do.

  1. Physical exercise
  2. Meditation
  3. Foods you eat and drink