The following are some of the most common delayed symptoms that car accident victims experience:nAbdominal pain can originate from internal soft tissue injuries, like organ damage or internal bleeding, which can be extremely serious or even fatal if you do not get treatment.nnBack pain can indicate a range of injuries, such as whiplash, a herniated disc, or a spinal cord fracture. Back sprains and muscle damage are also possible delayed car accident injuries.nnCognitive problems with memory and concentration or difficulty communicating can indicate a severe traumatic brain injury.