15
Apr

The Physiology Of Stress – In The Eye Of The Tiger

   Posted by: Dr. Tonia Mitchell ND   in Stress

This is the second of a three-article series that will cover stress in detail.  In the first article, I covered the sources and symptoms of stress.  In this article, we will cover the physiology of stress and look at why bad stress makes us sick.  In the last article, I’ll review some simple stress reduction techniques.

All of us have most likely heard about the fight or flight response.  In the face of danger, or a perceived negative stress (let’s use the classic example of a saber-toothed tiger), the chemistry changes in your body so that you can do one of two things: fight the tiger or run like stink to get away from it.  The goal of either option is the same: to survive the experience so that you can pass off your genes to your offspring.

In response to a stress (real or imagined) your nervous system reacts first.  Your brain sends a signal to a gland (like a hormone factory) called the hypothalamus.  This hormone factory sends chemical signals to different parts of your body such as the adrenal glands.  The nerve cells in the inside of the adrenal glands produce and release adrenaline and we see an increase in blood pressure, heart rate, breathing rate, muscle tension and metabolism.  The blood flows from your digestive organs to the major muscles in your body.  Your pupils get bigger so your vision becomes sharper.  Your hearing and concentration actually improve.  The hormone system reacts after the nervous system.  Eventually, the outer part of the adrenal glands secrete cortisol.

Cortisol has many important jobs in your body during acute stress:

  • Increases blood sugar levels in the body, providing the energy to fight or flee;
  • Acts as a powerful anti-inflammatory agent;
  • Increases blood pressure;
  • Follows a daily pattern with the highest level secreted at around 8:00 am (to help us wake up), after which there is a gradual decline throughout the day. Levels are lowest between midnight and 4:00 am (to help us sleep).

The physiology of stress prepares us to battle or bolt. Once we have evaded (or killed) the tiger, our system ideally returns to normal.  In modern society our saber-tooth tigers come to us in many forms as discussed in the first article of this series.  Often, our modern tigers don’t even require a flight or fight, but our body still reacts this way.  Many social norms (manners, customs, insecurities) prevent us from actually facing the stress or running away from it.  Also, our tigers are more chronic in nature.

We find the following stress patterns in our western world today:

  1. Our fight or flight response is often active even though there is no actual threat to our safety.
  2. We are faced with chronic stress.
  3. Social Courtesies prevent us from engaging in combat or cutting out.
  4. The stress response remains unchecked and builds up.
  5. The stress response build-up leads to the production and release of constant, unopposed cortisol.
  6. We become sick from the stress cycle.

The less desirable effects of cortisol on the body in the face of chronic distress include:

  • A suppressed immune system leading to a decrease in our resistance to infections, cancer, and illness;
  • An increase in blood pressure which can lead to stroke, aneurysm or heart attack;
  • A decrease in bone mass (in an attempt to supply the blood with ample amounts of nutrients);
  • A depletion of natural pain killers (endorphins) which can aggravate pain anywhere in the body;
  • A decrease in both male and female sex hormones leading to decreased libido, impotence, absent periods and infertility;
  • Inhibiting the function of the digestive system (which works best when we’re relaxed) leading to diarrhea, constipation, bloating, abdominal pain or other related concerns;
  • A decrease in insulin sensitivity leading to or aggravating diabetes;
  • An increase in liver production of cholesterol which gets deposited in the blood vessels leading to heart disease;
  • A thickening of the blood which can worsen your risk for cardiovascular disease;
  • An affect on the functioning of the thyroid gland and thyroid hormone which can cause changes to your metabolism.

As you can see stress is a big player in our state of health.  Since stress is unavoidable, what can you do about this?  You can change how you cope with stress and improve your body’s capability to handle it.  Don’t miss the final article in this series, “Stress Reduction Techniques – Breath or Die, and I’m Dead Serious

Naturopathic medicine is a safe, effective and natural approach to you and your family’s health.  Naturopathic doctors can and will empower you to live a healthy lifestyle while treating and preventing disease.  Find more information on the services I offer at Arbour Wellness Centre at Nanaimo Naturopathic Doctor.

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This entry was posted on Wednesday, April 15th, 2009 at 3:25 pm and is filed under Stress. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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