A person typically is stressed when positive or negative (e.g., threatening) experiences temporarily strain or overwhelm adaptive capacities.
Stress is highly individualized and depends on variables such as the novelty, rate, intensity, duration, or personal interpretation of the input, and genetic or experiential factors.
(Most stress-reduction techniques have their greatest utility as elements of a prevention plan that attempts to raise one's threshold to anxiety-provoking experiences.)
Some of the common defense mechanisms are: compensation, conversion, denial, displacement, dissociation, idealization, identification, incorporation, introjection, projection, rationalization, reaction formation, regression, sublimation, substitution, symbolization and undoing.
The stress may be an overwhelming traumatic experience (e.g. accident, battle, physical assault, rape) or unusually sudden change in social circumstances of the individual, such as multiple bereavement.
Symptoms show considerable variation but usually include: An initial state of "DAZE" with some constriction of the field of consciousness and narrowing of attention, inability to comprehend stimuli, disorientation.
This arises after response to a stressful event or situation of an exceptionally threatening nature and likely to cause pervasive distress (great pain, anxiety, sorrow, acute physical or mental suffering, affliction, trouble) in almost anyone.
Flashbacks are the repeated reliving of the trauma in the form of intrusive memories or dreams, intense distress at exposure to events that symbolize or resemble an aspect of the traumatic event, including anniversaries of the trauma, avoidance of activities and situations reminiscent of the trauma, emotional blunting or "numbness", a sense of detachment from other people, autonomic hyperarousal with hypervigilance, an enhanced startle reaction and insomnia, marked anxiety and depression and, occasionally, suicidal ideation.