Tuesday, 1 April 2014

Define Stress Terms

Stress overload fuels most of diseases afflicting modern humans. Roughly onethird of American adults feel routinely overwhelmed by stress. Children and teens aren’t immune. The authors of the American Psychological Association’s 2011 Stress in America survey noted that “the nation is on the verge of a stress-induced public health crisis.”

Before we go further, we need to define terms. The word stress has many connotations. Originally an engineering term, stress referred to the force applied to an object such that the object becomes deformed (squeezed, stretched, or bent). Researcher Hans Selye applied that term to human stress. A stressor is anything that activates a person’s stress response. Selye’s research showed that, regardless of the nature of the stressor (excessive heat, cold, pain, physical exhaustion, or social upheaval), organisms responded in a fairly predictable fashion.

During the stress response, the autonomic (mainly automatic and involuntary) nervous system shifts from the parasympathetic nervous system (rest and digest) to the sympathetic nervous system (fight or flight). As a result, respiratory rate, heart rate, blood pressure, and blood sugar rise. The pupils of the eyes dilate. Senses sharpen. The mouth dries. Skin becomes paler and cooler. Blood flow diminishes to nonessential organ systems (reproductive, urinary, and gastrointestinal). The goal is to deliver sugar and oxygen to organs critical for survival: the brain, heart, and skeletal muscles. When acutely stressed, you think and move quickly.

One of the sympathetic nervous system’s tasks is to release epinephrine (adrenaline) from the adrenal gland. That happens swiftly. After a delay, a hormone from the brain’s pituitary gland reaches the adrenal gland, triggering the release of cortisol. Cortisol’s main job is to keep blood sugar high (even if it means dismantling carbohydrate, fat, and protein stores). It also reduces inflammation and regulates the immune system. This hormone lingers longer in the system than epinephrine does.

Our stress response has survival advantages. Because our ancestors faced mainly physical stressors, the stress response was beautifully designed to help us perform impressive physical feats—fight, flee, and endure famines. While we continue to face physical challenges, many of our modern stressors are psychological. If you’re stuck in traffic, it does you no good—in fact, it can do much harm—to mount a stress response.

Worse, humans, unlike other animals, don’t always live in the moment. Our big brains are capable of rumination (mulling over past events) and anticipation. We relive past failures and embarrassments and fret over events in the distant future. Once you’ve learned from past events, let them go. Planning and preparation have merits. We save for a rainy day, study for exams, and prepare for meetings. Worrying, especially about things you have no control over, is useless and corrodes well-being. We often reward a harried, overworked lifestyle and regard the low-grade, chronic stress that comes with it as normal, even admirable.

The truth is, however, that chronic stress overload can shorten your life and ruin your health. It strains every organ system, contributing to many diseases and aggravating others. It reveals the vulnerabilities to diseases. (Stress finds your Achilles’ heel.) Coping with stress in maladaptive ways, such as skipping meals, abusing alcohol, and becoming a workaholic, accelerates the downward spiral.

No comments:

Post a Comment