Hypervigilance is one of the hyperarousal symptoms of PTSD
and refers to the experience of being constantly tense and "on guard." A person experiencing this symptom of PTSD will be motivated to maintain an increased awareness of their surrounding environment, sometimes even frequently scanning the environment to identify potential sources of threat. Hypervigilance is also often accompanied by changes in behavior, such as always choosing to sit in a far corner of a room so as to have awareness of all exits. At extreme levels, hypervigilance may appear similar to paranoia.