In our present-day busy lives, stress has become a buzzword. Everybody is under a lot of pressure. Due to everything you want and everything you have to do in your free time and on the job, it is your schedule that keeps control of your life. It is hard to find people who do not feel quite stressed regularly.
Stress is a very peculiar concept. Too much of it is extremely damaging to your health, but too little of it isn’t good for you either. You need just enough of it. But how much is enough differs for every individual. So, it is important to learn which level of stress is optimal for you and how much stress you can handle.
Stress is defined as a persistent mental strain. Originally, the term stems from the area of physics where stress has to do with mechanical strain that can lead to distortion of a material. The psychological meaning of the word recently became in vogue during the fifties of the past century thanks to the work of Hans Selye, a Canadian researcher from Hungarian descent. He defined stress as the process of transactions in which the resources of an organism are matched against the demands of the environment. Is the organism adapting well then it will feel positive stress. When the circumstances are unfavourable and the organism isn’t feeling at ease in its surroundings, it experiences negative stress.
Stress is a natural part of life. It is about whether you feel able to cope with the demands your environment poses. The appraisal of the importance of the demands is different for every individual. One person may flourish under a certain tension while another feels overwhelmed and can’t cope with the pressure. A third person in the same situation might be – almost literally – bored to death.
Situations can be experienced as challenging or threatening. When you think your resources approximate or exceed the demands of the situation, you will see it as a challenge. Your bodily reactions mimic aerobic exercise with an increased heart rate and decreased vascular resistance. If the demands seem to outweigh the available resources you will perceive the situation as a threat. Heart rate increases, but vascular resistance does not decrease, which results in an increase in blood pressure and possible health problems.
At an optimal level of stress, the brain is moderately aroused, your resources are mobilised, full attention is given to your surroundings, you are emotionally balanced and giving your best performance. When stress levels are too low, you become inattentive, distracted, and bored. Over-arousal leads to an impaired ability to respond selectively, feelings of excitement and tension, fragmentation of thought processes, loss of the ability to integrate messages into meaningful wholes, impaired judgment, and loss of initiative.
Stressors can be major life events, positive and negative, but also common daily hassles, called microstressors. Major life events can increase the susceptibility to accidents and illness, whereas microstressors are closely linked to immediate health.
Too much stress involves clearly recognisable warning signs. On the emotional level, these are anxiety, apathy, irritability, and mental fatigue. Behaviourally, too much stress leads to avoidance of responsibilities and relationships, extreme or self-destructive behaviour, self-neglect, and poor judgment. Physically, warning signs are physical ailments and complaints, frequent illness, exhaustion, and overuse of medication.
Of course, nature has made sure an automated response to stressful situations comes built-in. The most common response is the fight-or-flight response. All bodily resources are mobilised for a short period to deal with immediate physical dangers. For instance, heart and lungs will work faster; extra nutrients become available for the muscles; pupils will dilate; and metabolism will slow down or stop completely. When the danger has been averted the body soon returns to its normal functioning mode.
This response has helped man survive in the past when he had to deal with many predators. But being able to deal with threats from predators isn’t so useful anymore in modern day life. Still, many contemporary demanding circumstances activate the fight-or-flight response. Activating this system too often or for too long can become a serious health threat. The body isn’t returning to its normal functioning mode. The everyday business of body maintenance is put on hold. This includes the routine tracking down and destruction of foreign or errant cells that could cause diseases.
Humans nowadays have long-lasting problems, which result in long-term disruption of the body balance. This gives diseases more room to strike. Such a threat does not only come from too much tension, but also from a stimulus under-load when stress levels are too low.
One part of the brain is particularly sensitive to stress and that is the hippocampus, the brain area that plays a very important part in learning and memory. While under stress, the body produces the hormone cortisol. This hormone makes sure extra energy is available to be able to react adequately to a stressful situation. Cells in the hippocampus contain large quantities of receptors for cortisol. If sufficient cortisol has bound to the hippocampal receptors, signals are being sent to stop producing the stress hormone.
When the stress is severe and continuous the ability of the hippocampus to do its stress-control job falters. The mechanism to start producing cortisol is being activated again and again. The hippocampus can’t cope with the high levels of cortisol and becomes flooded with it. The stress hormones do not damage the hippocampus directly but start a chain reaction that may lead to the death of many neurones. Besides, long-term stress can cause atrophy of dendrites, the small fingers of neurones that have to catch and pass on signals. Stress hormones also negatively influence the prefrontal cortex, the brain’s executive area, which is why people often make bad decisions under stress and show increased aggression.
Another consequence of stress is that it inhibits neurogenesis, the birth of new neurones, in the hippocampus. This makes the hippocampus shrink. A direct relationship exists between the size of the hippocampus and memory performance. Thus chronic stress leads to impaired memory.
The changes in the hippocampus are reversible as long as the negative stress is terminated after a number of weeks. Longer stress periods result in permanent damage. The cumulative effect of stress starts taking a toll on health in middle age.
A connection has also been made between stress in midlife and the development of dementia in late-life. A large group of women in Sweden participated in a 35-year longitudinal population study. Those who reported repeated periods of stress in middle age run a 65 percent higher risk of dementia, mainly from Alzheimer disease, than the ones who did not report repeated periods of stress.
So it is a matter of utmost importance to take care of our hippocampus by de-stressing.
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