Of all the possible factors that can affect the autonomic nervous system, stress — both physical and mental — is the most common cause of imbalance.

We live in a world that surrounds us with an overwhelming amount of stress every day.

Wars and rumors of wars, terrorist attacks, government intrusion into our lives, rising taxes, crime, family disruption, moral decay, judicial abuse, racial tension and economic uncertainties all play their parts.

Studies have shown that intermittent, or occasional, stress actually makes us stronger.

But constant, unrelieved stress can be very destructive.

Our bodies respond to stress in a way that prepares us for “fight or flight,” which is a sympathetic overdrive reaction. If this is unrelieved it can lead to many illnesses, including hypertension, heart disease, strokes, atherosclerosis, a number of gut disorders, brain atrophy, memory loss, immune suppression, confusion, depression, anxiety, panic attacks and eventual heart failure.

Make no mistake: Stress is a major killer.

A study in the “Journal of Cardiovascular Translational Research” compared nurses who do shift work to those who work regular daytime hours.

The researchers found that the shift workers — who have much more stressful jobs than those who work regular hours — had prolonged, higher sympathetic nervous system activity than those working regular hours.

Other studies have shown that stress causes brain inflammation, which triggers sympathetic overdrive.

At the same time, the parasympathetic nervous system is suppressed and this makes us more prone to a number of problems, such as heart failure, arrhythmias and a number of digestive and gut problems.

Interestingly, the parasympathetic system is also important as an anti-inflammatory system — that is, it helps shut down excessive inflammation in the body.

Therefore, when it is suppressed we are more prone to uncontrolled inflammation.