When stress upsets the balance over time, the body transitions from the "resistance stage" - during which the organism makes efforts to cope with the threat - to the "exhaustion stage" - which occurs if the organism fails to overcome the threat and depletes its physiological resources.
Every person has in fact a limited amount of adaptive energy and this supply decline with continuous exposure to stressors.
In case of a continue state of arousal, hormones levels not return to normal because the body continue to react with a release of stress hormones.
This is very common nowadays. In our frantic and busy lifestyle, we are often in state of stress because the body overreacts to stressors that are not life threatening such as traffic jams, work pressure, and family difficulties. Simplify, we turn on the exact same stress response for purely psychological states as it is in case of "life or dead" situations.
This is why the popular perception of stress is closer to an abstract concept (a bad state of mind) rather than a natural process.
"Stress" is a buzzword for "time pressure": when we do not have the time to perform the tasks that we want to perform within a given period. We refer to stress also to talk about a general state of mental tension and strong feelings of worry or anxiety caused by life.
Even this popular definition of stress, scientific researches have proven that stress is more than a state of being and that it could be linked to different diseases. In fact when the stress becomes chronic the body starts to lose its ability to combat the stressors because the adaptive energy is all drained out.
We refer to "exhaustion stage" as the gate towards "burnout syndrome" (a physical and emotional collapse) or "stress overload" which can lead to health problems if not resolved immediately.
To better understand the concept check out this interesting reference synthetizes the stress process according to the Hans Selye’s GAS ("General Adaptation Syndrome") theory:
When the stress response is prolonged over the time (for instance when stressors are too frequent or in case of circular-thoughts) we are far from homeostasis. Stressors can come from different origins: a life-threatening situation such as a major physical trauma, prolonged starvation, bad image of our self or a mix of prolonged psychological stressors due to a frenetic lifestyle.
Excessive levels of cortisol release in our blood, may upset homeostasis and harm internal organs, leaving the body vulnerable to disease. In consequence stress-related tensions build because of the amount of stress-hormones our body is not able to handle.
We can recognize excessive level of cortisol in our blood through different symptoms such as high blood pressure, increased anxiety and mood swing. Here below you will find a complete overview of the symptoms of high cortisol level from Dr. Axe:
That said cortisol is much more than just a hormone released during stress. Cortisol is also important in terms of achieving a good health when present in normal level. Because most bodily cells have cortisol receptors, cortisol affects many different functions in the body. Cortisol can help control blood sugar levels, regulate cellular metabolism, help reduce inflammation and assist with memory formulation. It has a controlling effect on salt and water balance and helps control blood pressure. In women, cortisol also supports the developing fetus during pregnancy. Cortisol also regulates our circadian rhythms: cortisol level in normal individual are highest at around six to eight in the morning and are lowest around midnight.
All of these functions make cortisol a crucial hormone to maintain our internal balance. However, when stressors causing an organism's condition to over-release for a long time stress hormone (especially cortisol) unpleasant symptoms or linked diseases come out.