Post-traumatic stress disorder (PTSD) has a variety of signs and symptoms that can be divided into three categories. These include constantly being on edge, avoiding remembering or thinking about the traumatic event or re-experiencing the trauma, according to the National Institute of Mental Health.
PTSD is a condition in which the natural response of "fight or flight" is damaged in some way, NIMH reports. People with PTSD often experience the feeling that naturally occurs when a person feels like he is in danger when no danger is actually present.
One category of PTSD signs is hyperarousal, states NIMH. PTSD sufferers are often on edge or easily startled. They may have angry outbursts or difficulty sleeping. Hyperarousal symptoms also include feeling anxious and on edge.
Avoidance symptoms involve avoiding anything that reminds the PTSD sufferer of the traumatic event, explains NIMH. People may have difficulty remembering the event or begin to avoid anything that reminds them of the incident. They may lose interest in things they used to enjoy or begin feeling overly worried, guilty or depressed. Some report feeling emotionally numb.
Another set of PTSD signs include re-experiencing the event, says NIMH. These symptoms include frightening thoughts, nightmares and flashbacks, which are a reliving of the traumatic experience over and over again.