While post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) seem fairly different, they share many similarities, and this can make the proper diagnosis challenging. It's not uncommon for individuals to be diagnosed with both, and that can make it difficult to properly recognize, treat, and determine the life-altering effects of each disease. Being diagnosed with PTSD and TBI challenges an individual’s ability to navigate life the same way that they did before the injury.