The best way to link GERD to your VA claim is to get a competent and credible medical nexus letter. What's a NEXUS LETTER? Medical nexus evidence is one of the three basic requirements to service-connect GERD. It establishes a connection between the service-connected disability (PTSD) and the current disability (GERD). A medical nexus letter from a qualified medical professional provides competent and credible evidence of GERD. This letter contains all the required details required to help a vet