Douglas Harper's Etymology Dictionary
Wiktionary
n. An enhanced state of sensory sensitivity accompanied by an exaggerated intensity of behaviors whose purpose is to detect threats.
Wikipedia
Hypervigilance is an enhanced state of sensory sensitivity accompanied by an exaggerated intensity of behaviors whose purpose is to detect threats. Hypervigilance is also accompanied by a state of increased anxiety which can cause exhaustion. Other symptoms include: abnormally increased arousal, a high responsiveness to stimuli, and a constant scanning of the environment for threats.
In hypervigilance, there is a perpetual scanning of the environment to search for sights, sounds, people, behaviors, smells, or anything else that is reminiscent of threat or trauma. The individual is placed on high alert in order to be certain danger is not near. Hypervigilance can lead to a variety of obsessive behavior patterns, as well as producing difficulties with social interaction and relationships.
Hypervigilance can be a symptom of post traumatic stress disorder (PTSD) and various types of anxiety disorders. It is distinguished from paranoia. Paranoid states, such as those in schizophrenia, can seem superficially similar, but are characteristically different.
Hypervigilance is differentiated from dysphoric hyperarousal in that the person remains cogent and aware of their surroundings. In dysphoric hyperarousal, the PTSD victim may lose contact with reality and re-experience the traumatic event verbatim. Where there have been multiple traumas, a person may become hypervigilant and suffer severe anxiety attacks intense enough to induce a delusional state where the effects of related traumas overlap. This can result in the thousand-yard stare.
Usage examples of "hypervigilance".
The way I acted and thought, my hypervigilance and nightmares, made sense.
Standing quietly outside the cell beside Ekoor—who, like Reese, was still disguised as one of the Founder’s Breen guards—Reese completely understood the hypervigilance of the security people.
Standing quietly outside the cell beside Ekoor-who, like Reese, was still disguised as one of the Founder's Breen guards-Reese completely understood the hypervigilance of the security people.