How is stress defined?The word stress itself is a bit confusing in that it is used to describe two aspects of a threatening situation. First, it refers to an outside danger, an incident or situation that alerts you to protect or defend yourself, or to escape. In this sense it is synonymous with “danger,” even if the danger is only imagined. The word stress also refers to your physical and emotional response to these situations. In a dangerous situation, you might say that you experience stress.
Stress, in its definition as “outside danger,” is only partly avoidable, and the truth is you can’t always control it. Your body reacts to stimuli that appear to threaten its survival or well being. The brain perceives danger and reacts by activating physiological mechanisms to defend the body. This is our built in fight or Jlight response, a response that has become one of the foundations of classic teachings in physiology and psychology. The key here is the brain’s perception of which outside events constitute dangers or stresses.
What happens to the body when it perceives stress?The body has certain mechanisms to deal with perceived stress that are meant to protect it. Let’s say an out-of-controi truck is careening toward you and you only have a moment to react. Here are some ways the body will respond to this situation.
The adrenal glands step up their production of stress hormones (adrenaline, noradrenaline, and cortisol) that activate the following responses:
• The metabolism speeds up, i.e., the heart beats faster and pumps more blood, giving you strength, speed, and energy to run or defend yourself.
• Your breathing rate increases, oxygenating the body so that it can work harder and longer.
•Your muscles contract, in preparation for you to spring into action.
• There is an increase in platelet “stickiness” in your blood, causing it to clot more quickly, thus minimizing blood loss in case of injury.
•Your blood pressure rises, probably because your heart is pumping faster and the arteries are constricted, sending more blood to the muscles and brain.
• More blood flows to the arms and legs while less goes to the stomach, giving you energy where you need it most.
This is an example of acute stress , where a specific situation causes the body to respond in an appropriate way to protect itself.