Post-traumatic stress disorder (PTSD) is an anxiety disorder, the differential diagnosis of which includes generalized anxiety, somatoform disorder, major depression with or without psychosis, secondary chemical dependency and schizophreniform disorder. The epidemiology and etiology of PTSD are briefly discussed. Pharmacotherapy is presented. The purpose of this paper is to alert physicians of what to look for, since the clues are sometimes in the musculoskeletal system, but do not respond to Osteopathic Manipulative Medicine (OMM) treatment until the origin of the trauma is also discovered.