Post Traumatic Stress Disorder (P.T.S.D.) is a natural emotional reaction to a deeply shocking and disturbing experience. It is a normal reaction to an abnormal situation.

For a doctor or medical professional to be able to make a diagnosis, he has strict diagnostic criteria, which has to be met. He will do this by asking you a series of questions or listening to talk about an event or events in your life in which you feel significantly changed your behaviour. One recognized standard for assessing PTSD is the World Health Organization's ICD-10.

It was thought that PTSD could not be a result of "normal" events such as bereavement, business failure, interpersonal conflict, marital disharmony, working for the emergency services, etc, and most of the research on PTSD had been undertaken with people who had suffered a threat to life (e.g. combat veterans, especially from Vietnam, victims of accident, disaster, and acts of violence). It is now recognized that PTSD can result from many types of shocking experience.