05/20/2009 05:12 am ET Updated May 25, 2011

Post-Traumatic Stress Disorder SYMPTOMS

The three groups of symptoms that are required to assign the diagnosis of PTSD are

* recurrent re-experiencing of the trauma (for example, troublesome memories, flashbacks that are usually caused by reminders of the traumatic events, recurring nightmares about the trauma and/or dissociative reliving of the trauma),
* avoidance to the point of having a phobia of places, people, and experiences that remind the sufferer of the trauma and a general numbing of emotional responsiveness, and
* chronic physical signs of hyperarousal, including sleep problems, trouble concentrating, irritability, anger, poor concentration, blackouts or difficulty remembering things, increased tendency and reaction to being startled, and hypervigilance to threat.