Post-traumatic stress disorder (PTSD) is a condition resulting from experiencing war, crime, sexual assault, accidents, or another threat to one's life or from witnessing a threat to or victimization of another person. Flashbacks, hypervigilance, and frightening thoughts are some of many possible symptoms. Approximately 8 percent of people will experience PTSD in their lives, so it's likely you know a coworker with PTSD. As with a person with any other physical or mental health condition, you…