Short Version: Caluza vs Brown defined what is necessary for service connection: This has to be MEDICALLY Documented in your records:   1.  Current Diagnois.   No diagnosis, no Service Connection.   2.  In Service Event or Aggravation.   3.  Nexus, or Doctor's Statement close to: "The Veteran's (current diagnosis) is at least as likely due to x Event in military service"   This is also known as the "Hi