Traumatic brain injuries and concussions are rather common in contact sports, resulting in a variety of symptoms including dizziness, headaches, nausea, and sometimes loss of consciousness. The long-term effects of concussions are still being studied but researchers believe that cumulative blunt force trauma over a career may result in serious neurological conditions later in life. Objective biomarkers of concussion would allow doctors to detect minor brain injuries and treat athletes appropriately. New research published in JAMA Neurology has identified several proteins in the blood of professional hockey players that indicates damage to brain tissue.