A journalist asked some questions about the impact of stress on health. Here is my answer:
Stress was first defined by Seyle in 1936 as "the non-specific response of the body to any demand for change." The earliest experimental finding in psychology was the "Yerkes-Dodson law," which is an upside-down U curve relating "arousal" to performance. That is, moderate levels of stress improve how well you function, but, in a given situation, too much stress will drag you down.
The body is controlled by two nervous systems, which act in opposition (as for example the biceps and triceps muscles in your upper arm act in opposition). The "parasympathetic" system is associated with calm, the "sympathetic" system with arousal. The sympathetic system is designed to optimize your reaction to a physical emergency. It increases muscle tension, raises blood pressure, shuts down the immune and digestive systems (because they use a great deal of energy, which is now needed for the emergency), increases speed of thinking, speeds up reaction time, blocks off the sensing of pain, increases visual and auditory acuity.
When we are under stress, the sympathetic system kicks in, to some degree. The stress response can be anywhere between a mild annoyance to a murderous rage; a little worry to paralyzing terror. So, when we worry over extended periods of time, we raise our blood pressure, increase muscle tension, interfere with digestion and the immune system. The severity of these effects depends on the seriousness of the worry.
It is clear from the above that chronic high levels of stress are guaranteed to interfere with health. Raised blood pressure increases the risk of strokes and heart attacks. Interference with the digestive system means poorer extraction of nutrients from food, and also, because the digestive tract is very richly supplied with a nervous system of its own, problems there can lead to eating disorders, including obesity through addiction to foods that have an antidepressant quality, such as sugars and starches. Partial suppression of the immune system increases the risk of cancer of all kinds, and infections from viruses, bacteria and fungi.
Digestive problems and disease then in turn increase chronic stress, and this can lead to a negative feedback loop.
The following have a higher probability of occurring as a result of chronic stress, and are exacerbated for people already suffering these conditions:
It is important to note that chronic stress does not cause these conditions. For example, gastric ulcers will only occur if you have Helicobacter pylori in your stomach. However, an estimated 50% of people harbor this bacterium, but the lifetime incidence of ulcers is only about 10%. You can have the bacterium but be safe from ulcers if you are not under chronic stress.
Chronic stress has other effects as well. John Calhoun's work with rats showed that the first reaction to stress (in his case, induced by population pressure) is that many, but not all, individuals developed such physical reactions. At the next level, many females (but again, not all) failed to mother their young appropriately, so the next generation included rats with "personality disorders." At the highest level of population density, and therefore stress, social order broke down. Many males attacked their females and young, and males formed gangs that fought to the death. Look around at our world...
Re-read Seyle's definition of stress: "the non-specific response of the body to any demand for change." The problem is not the situation out there in your environment, but how you react to it. Seyle was a physiologist, so conceptualized this in bodily terms, but the logic applies more generally.
There are three ways of protecting yourself:
a) Put peace into your heart
People with genuine religious beliefs can protect themselves through the attitude "As God wills," "Insha'Allah," the lesson of Job. In Buddhist thinking is the concept of equanimity: simply accepting without judgment whatever happens. You can be an atheist and think like this. When you manage it, you are completely protected from the effects of difficult situations. While you maintain this attitude, you are free from stress.
This is why daily meditation is so powerful. During the time you mediate and put peace into your heart, your body will recover from the effects of worry and annoyance in your life. Also, in time, the peace spreads beyond meditation. For religious people, genuine communion with God has the same effect.
b) Improve your thinking
Fear is an appropriate response to a real threat. However, many people are tortured by anxiety, which is the "What If" monster: reacting with fear to situations that may never happen. Worry is the extended anxiety reaction, there in the background much of the time.
Similarly, anger is appropriate on occasion, but it is a hot coal you pick up to throw at someone: it's your hand that gets burned (this is a Buddhist saying). Holding on to anger hurts you, not anyone else.
Cognitive psychotherapy, whether applied by yourself or with the help of a professional, is a way of restructuring your thinking processes to reduce the thinking that leads to the stress reaction.
One of my 15 books is on this subject: Anger and Anxiety: Be in charge of your emotions and control phobias. It is available as an e-book at Twilight Times Books or the usual outlets.
c) Positive psychology
Positive psychology is based on the fact that building on your strengths is as effective as improving your weaknesses. Following this approach, you can become confident that whatever the world throws at you, you will cope.
One of my books is a real life example of how inner strength can overcome the worst the world can throw at you. This is the biography Anikó: The stranger who loved me.
Finally, suffering, even physical disease, is not entirely bad. It is the spur to growth: no point changing anything if your life has nothing wrong with it. My inspirational novel Ascending Spiral: Humanity's last chance shows how suffering is the heat and pressure that turns a lump of coal into a diamond.
Calhoun, John B. (1962). Population density and social pathology. Scientific American 206 (2): 139-148.
Seligman, Martin (1991). Learned Optimism: How to Change Your Mind and Your Life. New York: Knopf.
Seyle, H. (1956) The stress of life. New York: McGraw-Hill.
Yerkes, R. M. & Dodson, J. D. (1908). The relationship of strength of stimulus to rapidity of habit formation. Journal of Comparative Neurology and Psychology, 18, 459-482.