Mental health articles

Sometimes it is helpful to understand a little more about the physiology of stress. Like each and every animal on this planet, we, the human animal, have a nervous system that “runs” our bodies without us ever thinking about it: it is called the Autonomic Nervous System (ANS). This organizes the heart, lungs, kidneys, muscle tone, hormones, digestion, etc., all below the level of consciousness. The ANS is divided into two separate halves: the sympathetic, the activity adrenalin-based half, and the parasympathetic, the relaxed digestive half. The sympathetic is the emergency response system: the “fight-or-flight” mechanism.

Imagine a deer or antelope grazing gently on the plains of the Serengeti: pure parasympathetic activity. It then smells a predator: its ears go up, the eyes widen, the head turns from side to side, it becomes very alert, its muscles are tense ready for “fight” or “flight”—totally sympathetic. These reactions are the affects of adrenalin that is now flooding through the animal preparing each part of its body, each organ, for this survival situation. In such a situation, your muscles become ready to act instantly; your mind becomes more alert; your heart rate speeds up; adrenalin slows or shuts down your digestive system, speeds up your breathing, releases sugar for quick energy, and so forth: all perfectly designed to prepare your body to act physically in an emergency. The digestive system closes down, as you do not want to be digesting your lunch when you are trying to prevent yourself from becoming someone else’s lunch. The blood retreats from the skin, to be available for the muscles.

The muscles prime themselves and the heat rate speeds up, ready for instant action—fight or flight. Back to the Serengeti: if the antelope runs away, or has to fight, that is fine! Most of the stress hormones (cortisoids) are then burnt off in the resulting intense physical activity. But if the animal does not have to fight or run, then eventually it gently relaxes, goes back to digesting its food and manages to digest some of the stress hormones as well: this is also fine. But … and here we have a problem … the human animal is NOT in the plains of the Serengeti, near where it originated. We have buses and bosses, trains and time schedules, school runs or spring-cleaning. We are continually under stress. On the Serengeti, we might only be chased once every two or three weeks, if we are unlucky.

Now we get stressed three or four times in a day—if we are lucky! So what happens to us, the human animals, is that the stress hormones and the by-products of adrenalin are notburnt off, or digested. They stay around, and then the next stress situation adds some more. These layers of stress eventually build up into a mass, or a block, which cannot be burnt off or easily digested. This physiological condition is called the “metabolic syndrome”: a cluster of symptoms, including high blood pressure, insulin resistance, high cortisol levels, and high cholesterol, which can double the risk of heart disease and diabetes. This build-up of stress also has a tendency to escalate the level of the next stressful situation, so that we also experience a build-up of emotional stress. This quickly spirals. All this means that instead of spending most of our time down at the parasympathetic end of the spectrum with only a few excursions into stressful situations (sympathetic), as do most other animals, we spend most of our time at the higher stress end of the spectrum (dashed double-arrowed line) with only the occasional excursion into healthy relaxation. No wonder we’re in such a state! The result of this unnatural imbalance in our essential physiology is that, collectively and individually, we suffer from a large number of stress symptoms: not because there is anything particularly wrong with us, but because there is something seriously wrong with the way that we live our lives nowadays. Our “normal” lives are not “natural” now.

Our basic DNA differs from chimpanzees only by about 4%, so put a chimpanzee down in the middle of London or Edinburgh and it would probably not survive more than a few minutes before it was a gibbering wreck. Ever been shopping there on a Saturday in August or just before Christmas? Know the feeling? This is our basic physiology talking to us. It is stressful! Therefore, we have to exercise more, to burn off most of the stress hormones, and to find more ways to spend more time just relaxing, so as to digest the stress residues and get ourselves back into physiological balance. The combination of exercise and relaxation does this wonderfully; it is also essentially free, and instantly available. We have to f ind many more ways of doing things in a much more relaxed way. We have to pay much more attention to the physiological “costs” of living our modern lives, and especially in modern cities, and then compensate for these.

Tags: physiology, stress