Post Traumatic Stress Disorder (PTSD) happens after someone experiences something extremely frightening, like violence, abuse, rape or a life threatening situation. PTSD can also affect you if you were a witness to a frightening situation. With PTSD someone would find it extremely hard to move past the traumatic event and they would carry on having dreams, flashbacks or upsetting thoughts about the event. It's important to know that it isn't just army veterans that experience PTSD, lots of people experience it after being exposed to a traumatic event.