At least 1.4 million people die, or receive hospital or emergency care every year in the United States as a result of traumatic brain injury (TBI). Many more are treated in other settings or receive no treatment at all. Thus TBI is often unidentified, with subsequent cognitive, behavioral, emotional and physical sequelae that are not linked to the injury. Yet, over 5.3 million Americans live with TBI-related disabilities that interfere with their overall performance and social roles within the community. The pathophysiology and consequences of TBI are discussed, as are functional changes and psychiatric manifestations after TBI. Finally, implications and recommendations for clinical practice are reviewed, including the importance of screening for TBI.