When is post traumatic stress actually post traumatic stress disorder ?

Stress vs Disorder: Great question. Exposure to an event or events involving actual or threatened death or serious injury, or a threat to the physical integrity of self or others -- is the first step. The person's response includes intense fear, helplessness, or horror. The crucial thing distinguishing a disorder is that a lasting syndrome develops, causing distress and disruption in social, work, or other areas.

PTSD: First, an individual goes through or witnesses an event that is outside the realm of normal, every-day human experience. If he/she has strong coping skills, it's just a bad experience. However, if coping skills are strained and fail, one can develop acute stress disorder if within 30 days of the event. After approximately one month, the diagnosis of ptsd can be made.