The stress response, sometimes called the fight or flight response, is your body’s natural response to environmental demands. Positive stress helps us react to emergency situations and adds anticipation and excitement to our daily lives. Excessive and chronic stress leaves us feeling overwhelmed. Stress can be both friend and foe.
The Stress Response
Stressors, which can be either physical or emotional situations, trigger the stress response. The hypothalamus, which is located in the brain, responds to stress by stimulating the release of ACTH ( adrenocorticotropic hormone) from the anterior pituitary gland.
ACTH signals the adrenal glands to increase production of the hormones, epinephrine also called adrenaline, norepinephrine also referred to as noradrenaline and cortisol. (1, 2)
These hormones prepare you to fight or flee by dilating your blood vessels and shunting blood from your skin and digestive system to your large muscle groups. Your pupils dilate to improve vision. Heart rate, respiratory rate and metabolism increase.
The stress hormones signal your liver to release stored glucose to increase your energy. Sweat production increases to help cool you down. These physical changes prepare you to act quickly and effectively to handle the stressor.
Benefits of Positive Stress
Positive stress helps keep you motivated to complete a task or to make necessary changes in your life. Discoveries and creative solutions can result from positive stress. Good stress aids you in confronting or escaping a threat. Short term stress may enhance the function of your immune system.
An animal study conducted by Firdaus Dhabhar, an assistant professor of oral biology at Ohio State University, suggests that short periods of stress, typically not longer than a few hours, may actually be beneficial. The immune system may respond to stress hormones and release gamma interferon, which is one of a group of immune system hormones called cytokines. Cytokines regulate the immune response. (4)
Negative Effect of Chronic Stress
Untreated chronic stress leads to chronically elevated cortisol levels. Overexposure to cortisol alters immune system responses, leads to memory impairment and suppresses the digestive system, the reproductive system and growth processes. Prolonged exposure to the stress hormones increases the risk for developing heart disease, obesity, sleep disturbances and depression. (5)
Sources:
(1) Brown University Health Education: Stress, Nov. 7, 2011
http://brown.edu/Student_Services/Health_Services/Health_Education/commo...
(2) Wisc-Online.com: the Stress Response by Barbara Liang, Nov.7, 2011
http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP13804
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(3)TeensHealth from Nemours: Stress, Nov. 7, 2011
http://kidshealth.org/teen/your_mind/emotions/stress.html#
(4) The Ohio State Research News: Short Bursts of Stress May Enhance the Immune System Function (March 6, 2000), Nov. 7, 2011
http://researchnews.osu.edu/archive/intrfron.htm
(5) Mayo Clinic: Stress Management, Nov. 8, 2011
http://www.mayoclinic.com/health/stress/SR00001
Reviewed November 9, 2011
by Michele Blacksberg RN
Edited by Jody Smith