Post-traumatic stress disorder (PTSD) is a disorder that may occur in people who have experienced or witnessed a dangerous, shocking or traumatic event such as rape incident, war or accident, earthquake or flood. Symptoms usually begin early, within 3 months of the traumatic incident, but sometimes they begin years afterward. Symptoms must last more than a month and be severe enough to interfere with relationships or work to be considered PTSD. Bad dreams, Flashbacks- replaying the trauma over and over, Frightening thoughts, including physical symptoms like a racing heart or sweating, are characteristics of PTSD.