Sleep problems is the physical characteristics that should you look for in a soldeir who is suspect of having Post Traumatic Stress Disorder.
Changes in breathing patterns (i.e. shortness of breath)
Lack of energy OR Sometimes being very active and over-energetic
Feeling of emotional pain that you have never felt before
Hyper vigilance (always on alert)http://veteransfamiliesunited.org/2011/06/06/post-traumatic-stress-disorder-symptoms-and-resources/