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 that can cause exhaustion. Other symptoms include: abnormally increased arousal, a high responsiveness to stimuli, and a continual scanning of the environment for threats.
In hyper vigilance, 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.
Hyper vigilance can lead to a variety of obsessive behavior patterns, as well as producing difficulties with social interaction and relationships.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, DC. American Psychiatric Association. 2013. Internet. Accessed on June 21, 2017.