Posttraumatic Stress Disorder (PTSD) can occur when someone has experienced, witnessed, or faced threat of serious harm to themselves or a loved one. These traumas include natural disasters, terrorist acts, sudden death of a loved one, military combat, serious accidents or injury, and sexual or physical assault as a child or adult.
After the trauma, those who develop PTSD experience four main types of symptoms:
Reexperiencing: flashbacks, nightmares, intrusive thoughts and images of the event
Avoidance: emotionally numbing and avoiding people, places, and things that are reminders of the trauma
Negative changes in thoughts or mood: difficulty remembering parts of the trauma, blaming and having negative beliefs about oneself and others, feeling isolated, and difficulty feeling positive emotions.
Increased arousal or reactivity: difficulty sleeping, problems concentrating, feeling irritable or on edge, feeling jumpy, and being easily angered.