Efforts, challenges, threats, or perceived threats or damage (physical and/or psychological) puts pressure on our biosystem. We thrive on various pressures to experience, adapt, survive, learn, and to live. Muscles can develop from putting pressure on them and they will atrophy without that work. The same principle applies throughout our physical system, and our brain as well (emotion and intellect). We depend on pressure and grow by challenging ourselves. We will define healthy systemic pressure as eustress. This is differentiated from what we commonly call stress. In engineering terms the concept of stress say on a steel I beam in a high rise building can lead to metal fatigue and the actual physical breaking of that beam, which could potentially lead to the breaking and even collapse of that building. We will follow the convention of using stress to mean bad stress.
Despite this, please regard stress as basically good. People can subject themselves to so much exercise that they loose strength and endurance. They use up their muscle tissue faster than they rebuild it. Then the healthy stress on their muscles becomes destructive.
Chemically, we need adrenaline and choline systems, adrenergic and cholinergic systems.
We need our bodies’ hormonal systems to use and build our muscles. The body’s hormonal systems also keep a homeostatic balance.
In psychological stress, the body shifts into the fight or flight mode. Our body prepares for immediate physical action. These systems too can suffer atrophy or exhaustion. We can directly see and feel the body’s responses to some kinds of stress. We sweat and flush from muscular effort; we get goose bumps and pale skin from cold. We can even hear fatigue or shivering in a person’s voice.
Primarily hidden symptoms accompany the shift from benign to pathological stress. We cannot so easily see, hear, or feel sleeplessness, irritability, and inability to concentrate. For most of us, only mechanical medically related instruments reveal blood pressure gradually elevating to dangerous levels, and body chemistry going out of balance. Sometimes the body cannot maintain the range of temperature necessary for adequate functioning.
Sometimes people persist in exercising, working, or even playing to exhaustion. Either can lead to collapse and eventual death. The body also suffers other types of collapse when other types of stress press it beyond its limits.
When under stress, the brain shifts its transmitter balance. This prepares the body to deal with the stress. If the stressing agent remains present (stressful conditions on the job, in the home, etc.) the shift may become permanent. The body and the personality of the
individual can suffer from such permanent shifts away from healthy homeostasis. This brings patients to medical treatment facilities.