What is post-traumatic stress disorder (PTSD)?

Post-traumatic stress disorder (PTSD) is an anxiety disorder that a person can develop after experiencing or witnessing—either directly or indirectly—a traumatic event or life-threatening situation. A traumatic event involves exposure to death, threatened death, actual or serious injury, or actual or threatened sexual violence. Specific examples include physical assault, combat exposure, and serious accidents.

Who develops post-traumatic stress disorder (PTSD)?

In the United States, approximately 7-8% of the population will develop PTSD at some point in their lives. It is not known why some people suffer from PTSD after a traumatic event and others do not. However, researchers have identified specific factors that increase risk for PTSD:

  • Experiencing trauma caused by other people, such as rape or assault;
  • Exposure to long-term or repeated traumas;
  • Personal history of mental health problems, especially anxiety disorders;
  • Lack of support from family and friends after a trauma.

What are the symptoms of post-traumatic stress disorder (PTSD)?

People who have PTSD may have the following symptoms:

  • Repeated, intrusive memories of the traumatic event
  • A vivid sense that the traumatic event is happening again (also called a “flashback”)
  • Nightmares about the event
  • Intense distress after being reminded of the event
  • Physical symptoms of anxiety, such as nervousness, being startled easily, an inability to concentrate, and insomnia
  • Persistent negative emotions about the event, such as guilt, shame, fear, or anger
  • Avoiding reminders of the traumatic event
  • Amnesia for all or part of the event
  • Decreased interest in things that were once important
  • Feeling hopeless about the future

If these symptoms last longer than a month and interfere with the person's social life, work, or relationships, they may represent PTSD. Most symptoms of PTSD usually occur within three months of the traumatic event, but can emerge years later. Not everyone who experiences a traumatic event will have PTSD.