Post-traumatic stress disorder (PTSD) is a form of chronic psychological stress that follows exposure to a traumatic event, such as a natural disaster, a violent crime, an accident, terrorism, or warfare.

PTSD symptoms include the following:

  • recurrent, intrusive, distressing dreams (nightmares) and memories of the trauma
  • a sudden sense that the event is recurring; experiencing flashbacks
  • extreme distress when confronted with events that symbolize or resemble the trauma
  • attempting to avoid thoughts, feelings, and activities associated with the event
  • inability to remember aspects of the trauma
  • markedly diminished interest in important activities
  • feelings of detachment and estrangement from loved ones
  • low expectations for the future
  • insomnia or excessive fatigue
  • extreme irritability
  • inability to concentrate
  • hypervigilance or an exaggerated startle response

Symptoms must last at least one month for a diagnosis of post-traumatic stress disorder. In the acute version of the syndrome, symptoms begin within six months of the trauma. The chronic syndrome may be delayed in its onset until more than six months after the event or may persist for more than six months afterward. As many as 15 percent of people involved in a major natural disaster suffer enough distress to need treatment.

PTSD complications include:

Overall, 7.7 million adults (3.5 percent of adult Americans) develop PTSD each year. It can develop at any age and tends to affect women more than men.

Publication Review By: Karen L. Swartz, M.D.

Published: 31 Jan 2001

Last Modified: 01 Oct 2015