|Any event or situation that requires a
nonroutine change in adaptation or behavior. Often it is unfamiliar
or creates conflict among motives within the individual. It may pose
a challenge or a threat to the individuals well-being or self-esteem.
|One that has a direct effect on the body.
This may be an external environmental condition (heat, cold, noise)
or the internal physical/ physiologic demands of the human body. The
body can acclimatize to some degree to some physical stressors.
|One in which only information reaches
the brain with no direct physical impact on the body. This information
may place demands on either the cognitive systems (thought processes)
or the emotional system (feeling responses, such as anger or fear)
in the brain. Appropriate exposure to mental or emotional stressors
can increase tolerance to them. Physical stressors can also be mental
stressors if they are perceived as dangerous threats.
|Any stressors occurring during the course
of combat-related duties, whether due to enemy action or from the
soldiers own unit, leaders, and mission demands, or the soldiers
|The mobilization of the body and mind
to counteract stressors. It involves the physiological reflexes that
ready the body for fight or flight. It also involves mental reactions.
Effects include decreased blood flow to skin, muscles, and heart;
increased sweating; adrenaline release for energy and alertness; muscle
tension; and interference with sleep.
|Positive stress (Eustress) is that degree
of stress that helps sustain and improve tolerance to physical and
emotional stressors without overdoing the experience. Eustress can
help the individual to function better, stay alive, and cope. The
purpose of stress in nature is to keep individuals in that range of
physiological, emotional, and cognitive mobilization that best enables
them to survive and reproduce. In military operations, however, the
soldier must accomplish the military mission, whether that contributes
to individual survival or not.
of stress to task performance
There is an optimal range of stress for any given task. If there
is too little stress, the job may be done haphazardly or not at
all, because the individual is easily distracted, makes errors of
omission, or falls asleep. If stress is too intense, the individual
may be too distractible or too focused on one aspect of the task
and may have difficulty knowing when and how to act. Extreme stress
may also impair coordination and concentration. With extreme stress,
the individual may freeze (become immobilized by fear). Alternately,
he or she may become agitated and flee in disoriented panic. If
stress persists too long, it can cause physical and mental illnesses.
Extreme stress with hopelessness can even result in rapid death.
|Weariness and/or decreased performance
capability due to hard or prolonged work or effort, muscle tiredness,
aerobic fatigue, and sleep deprivation. Physical illness can also
bring on fatigue. Intense emotions also produce physical fatigue.
This is especially true of anxiety and fear, because they arouse the
fight or flight reflexes of the physical stress process.
|Impaired performance due to continued
mental effort on a specific task, whether it is a task requiring much
thinking or constant attention. A brief break often relieves mental
fatigue and improves performance. Emotions, such as boredom or uncertainty,
also produce mental fatigue.
|Unacceptable and even criminal ways to
discharge or escape stress. Examples include substance abuse, brutal
violence, recklessness, desertion, malingering, and fraternization.
Army Center for Health Promotion and Preventive Medicine