PTSD, or post-traumatic stress disorder, is an anxiety problem that develops in some people after extremely traumatic events, such as combat, crime, an accident or natural disaster.
People with PTSD may relive the event via intrusive memories, flashbacks and nightmares; avoid anything that reminds them of the trauma; and have anxious feelings they didn’t have before that are so intense their lives are disrupted.
Adapted from the Encyclopedia of Psychology