What Is Stress? - Coping with Stress

What Is Stress?

In 1925, Hans Seyle, a European physician trained at the German University in Prague, noticed that all his patients displayed the same symptoms, including fatigue, aching bones and joints, fever, and appetite and weight loss. He subsequently developed the concept of “stress”–and the body's adaptive reactions to any demand, or “the rate of wear-and-tear caused by life.” In his book Stress Without Distress, Seyle explains how a number of agents can cause stress, including intoxification, trauma, nervous strain, heat, cold, muscular fatigue, polluted air, and radiation.

According to Seyle, the body reacts to stress in the same way it reacts to danger–by going through a series of biochemical changes which he called the General Adaptation Syndrome (GAS). In the first stage, which he termed “the alarm reaction,” the body mobilizes its defenses against the stressor agent. Nerve impulses from the brain stimulate the adrenal medulla to secrete adrenalin and other stress-related hormones such as cortisol. This is known as the “fight or flight” response: the heartbeat is accelerated, blood pressure levels are elevated, an increased amount of blood flows to the muscles, and the lungs dilate to increase respiratory effort.

Seyle called the second stage of the General Adaptation Syndrome the “resistance” phase–the phase during which the body continues to fight the stress or long after the effects of the “fight or flight” response have worn off. If the stress is induced by infectious agents, the body's immune system activity increases. If the stress is physical, the neuroendocrine system converts protein to energy. If the stress is psychological, a combination of responses may occur.

Prolongation of the resistance reaction or continued stress can lead to “exhaustion,” the third stage of the General Adaptation Syndrome. During this stage, glucocorticoid reserves become depleted and some body cells do not receive sufficient amount of glucose or other nutrients.

Exhaustion may manifest itself in a total collapse of body functions or a collapse of specific organs. Prolonged stress can overwork many organ systems, especially the heart, blood vessels, adrenals, and immune system. When stress is overwhelming, the response is general depression, low blood pressure and heart rate, increased cortisol (natural steroid hormone), and low sex steroid hormone secretions. Failure to cope with stress can lead to stress-related disorders such as headaches, hypertension, heart disease, stroke, and ulcers.

Measuring Stress Levels.     Many people may not be aware that they are undergoing stress. To help people assess their own stress levels, Drs. Thomas Holmes and Richard Rahe developed a list of potential stressors that have been linked to medical disorders. The Social Readjustment Rating Scale (see below) ranks stressful life events. The highest value, 100 points, is attached to the most grievous loss, the death of one's spouse. The scale demonstrates that stress is cumulative. For some people, it may take only a few significant events, or a number of smaller events, to overload the adaptive system of the body.