A concussion is a mild traumatic brain injury that results from a bump, violent jolt or blow to your head that disrupts normal brain function. A concussion can also be caused by a hit to your body that is strong enough to cause your head to forcefully jerk backwards, forwards or to the side.
Concussions stretch and bruise nerves and blood vessels and cause chemical changes in your brain that result in a temporary loss of normal brain function. A single concussion usually doesn’t cause permanent damage to your brain. Multiple concussions over a lifetime may result in structural changes in your brain.
Concussions are not usually life-threatening. However, the effects from a concussion can be serious and last for days, weeks or even longer.