Several things can happen after a head injury that signal the person should be treated in a hospital emergency department, says Bill Paolo, MD, an associate professor of emergency medicine and of public health and preventive medicine at Upstate. A loss of consciousness, nausea, vomiting and amnesia can be signs of  moderate or traumatic brain injury. Also, those younger than 2, older than 65 or who are taking blood-thinning medication may be more at risk from a head injury and should probably be evaluated at a hospital. Paolo explains how head injuries are treated and what kinds of testing to expect in the emergency department.