Concussion is a traumatic brain injury that affects your brain function. Effects are usually temporary but can include headaches and problems with concentration, memory, balance, and coordination.Concussions are usually caused by a blow to the head. Violently shaking of the head and upper body also can cause concussions.Some concussions cause you to lose consciousness, but most do not.Falls are the most common cause of concussion. Concussions are also common if you play a contact sport, such as football or soccer. Most people usually recover fully after a concussion.This can lead to bruising and swelling of the brain, tearing of the blood vessels, and injury of the nerves, resulting in a concussion, which is a traumatic brain injury. You do not need to lose consciousness to have had a concussion. Common causes of concussions include falls, motor vehicle accidents, sports, and work-related injuries. Most concussions do resolve with rest but those with symptoms lasting more than 2-3 weeks would benefit from skilled physical therapy to return to normal function.