How does post traumatic stress disorder affect war veterans? doesn't it affect all persons with bad experiences?

Whoa......: There is a big differance between a bad experience and an experience that is traumatic enough to cause a lasting traumatic stress disorder1. A traumatic stress disorder typically arises when in no way the patient has 'even a little control over the event. The preicpitating experience is "shocking to the patient. The resultant stress arises not onlyfrom loss, but from a feeling of total surprise.

Not all: Not everyone who goes through a life-threatening experience ends up with ptsd. A lot depends on immediate response to the event -- making sure there's needed medical care, food & water, getting to safe place, available but non-intrusive emotional support, etc. Also some factors increase vulnerability: previous trauma, depression or anxiety d/o's, substance abuse, social isolation, etc.

Threat of death: PTSD is a post trauma reaction to being in the situation of impending real or perceived loss of life, or inability to is scape. Examples of this would come from being in combat situations, or severe physical or sexual abuse. There are degrees of PTSD, it is not a matter of either the patient does or does not have it, it's not all or none.