The Physiology of Stress… Simplified!

With our current economic state, it is inevitable for many to feel more stress than usual.  A little bit of stress can be good at times, but when stress becomes prolonged or consistent in one’s life, the effects can have a negative impact on the body.  So let’s discuss the physiology of stress to better understand why it is essential to keep it under control, and ultimately keep the body in a state of optimum health.


When someone is stressed, they are said to be in a “Fight or Flight” mode.  Essentially, their sympathetic nervous system becomes over-stimulated, giving the person a momentary boost to do whatever needs to be done to survive.  Examples of short-term stress include being stuck in traffic, watching a scary movie, feeling excited or nervous before a race, and witnessing a traumatic event.  Thanks to hormones and the nervous system, the following processes will occur:

  • The heart will beat harder and faster to supply blood to the muscles needed for the activity.
  • The respiratory rate will increase in order to bring more oxygen into the body.
  • The body will breakdown fats and form sugars at an increased rate to meet higher energy demands.
  • Certain processes such as digestion and urine production will slow since blood shifts from non-vital organs to vital organs and muscles.
  • Inflammatory and immune responses will be inhibited since healing is not essential when the body is in a state of survival mode.

Once the stressful stimulus is removed, the body will gradually return to a normal resting state.


When stress becomes consistent or frequent in one’s life, it is termed chronic stress.  Examples of chronic stress include work, deadlines, family matters, financial stresses, disputes and schedules just to name a few.  The same processes discussed above will take place.  However, the body will eventually fatigue or “burnout” from trying to keep up with the increased demands.  Let’s look more closely at the impact stress can have on the body if prolonged without periods of rest and relaxation to counterbalance the stress response.

  • If the heart beats persistently harder and faster, other conditions such as high blood pressure, heart disease or heart failure can eventually develop.
  • If the body continues to demand more energy, it will start to breakdown proteins once sugars and been utilized and fat stores have been depleted.  This essentially means that it will start to breakdown much needed muscle tissue.
  • With digestion and urine production being impeded, other conditions such as constipation, ulcers, and kidney stones can subsequently develop.
  • Last but not least, it is much easier to become ill when chronically stressed because the immune system is suppressed, making the body more susceptible to everything from cold and flu to cancer.

Ultimately, the body doesn’t recognize what type of stress it is encountering.  Whether it’s acute or chronic stress, it will react the same way.  It is necessary for these reactions to take place, especially in an emergency situation.  However, we don’t want our body to be stuck in survival mode for long periods of time since it can lead to disease and premature death.

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