A traumatic event is an event that involves a threat to one’s own life or body, or involves witnessing a life threatening event that someone else faces.
If you or a friend have experienced a trauma it is helpful to know what to expect. Most people will experience some of the symptoms mentioned in this list after a trauma - you are not going crazy, this is normal. It is a really good idea to seek professional trauma counselling so that these normal symptoms do not turn into PTSD - a long term and complicated reaction to trauma.