A method of diagnosing central nervous system injuries such as acquired brain injury (ABI) and/or acquired spinal cord injury (ASI), including mild TBI (concussion or blast wave), mild ASI (contusion, stretch or partial cord transection), non-TBI brain injury and/or non-TSI spinal cord injury in a subject (animal or human). The method includes (a) obtaining a biological test sample from the subject, identifying metabolites in the subject's sample using metabolomics thereby obtaining a subject's metabolite matrix and generating a subject's profile using the patient's metabolite matrix; and (b) using multivariate statistical analysis and machine learning to compare the subject's profile with predetermined set of profiles of CNS injuries and a predetermined set of profiles of controls to determine if the subject has a CNS injury.