PTSD is usually caused by an extremely traumatic moment. For ie - soldiers, accident victim, hostage victim, rape survivor, etc. you get overly-stressed/incapacitated/frightened/etc. when triggered by a certain thing that reminds you of that moment. the worst worst worst worst thing about PTSD is that it makes you relive that traumatic moment vividly... and it will continue to make you relive it forever. that's why people wish they can erase it from their memory.
There are various forms that a person can suffer from PTSD -
1. unable to sleep well at night everyday because of reoccurring nightmares.... and the person would wake up in cold sweat. (this is the most common sympton for people with PTSD)
2. or a war veteran can function normally until he hears a sound of helicopter or explosion (even from balloon) and he would hallucinate or be extremely disoriented that he thought he's in a war zone.
My best friend is an ex-Army Rangers. You can see him in a highly-publicized news of Afghanistan rescue mission. The rescue mission was a botch-up job but he's very lucky to be in one piece. Because of that, he does suffer from PTSD but it's under controlled right now. when he came back home (his 3-years contract was up), it was pretty bad and also he wasn't the same as I knew him. He was bit disconnected from the reality. In NYC - you hear all kinds of noise.. helicopter/plane flying by everyday, sirens, etc. Sometimes at night when the plane/copter fly by, he would duck under his bed, screaming thru radio. or sometimes when there's certain noise that resembles explosion or gunshot... he would break into cold sweat and get paranoid.
after long sessions with therapist... he's doing pretty good. i wish I knew about ptsd at that time because i thought he was joking. but no... it was no joking matter. it's a serious issue.
Ooops... thanks for gettin' my attention. I will go over there then. LOL