Post-Traumatic Stress Disorder, PTSD, is an anxiety disorder that can develop after exposure to a terrifying event or ordeal in which grave physical harm occurred or was threatened. Traumatic events that may trigger PTSD include violent personal assaults, natural or human-caused disasters, accidents, or military combat. PTSD is an anxiety disorder that some people get after seeing or living through a dangerous event.

When in danger, it’s natural to feel afraid. This fear triggers many split-second changes in the body to prepare to defend against the danger or to avoid it. This “fight-or-flight” response is a healthy reaction meant to protect a person from harm. But in PTSD, this reaction is changed or damaged. People who have PTSD may feel stressed or frightened even when they’re no longer in danger.