CTE stands for Chronic Traumatic Encephalopathy, which is a degenerative brain disease found in athletes, military veterans, and others with a history of repeated head injuries. It is caused in part by repeated traumatic brain injuries, which include concussions and nonconcussive impacts. CTE is characterized by the buildup of a protein called tau in the brain after repeated head impacts, which can lead to brain damage similar to that seen in Alzheimers disease. Symptoms of CTE include loss of memory, confusion, flawed judgment, physical problems, and other behaviors. Football, hockey, boxing, soccer, and rugby are among the contact sports that make players most likely to have CTE. There is currently no way to definitively diagnose CTE during life, but experts have developed clinical criteria for traumatic brain injury and CTE.