I think many of us are too accustomed to thinking a concussion is not too much of a big deal. But in fact, it is a brain injury because when someone has a concussion and they have symptoms of a concussion from memory loss, being blacked out or whatever, those symptoms are caused by damage to the brain cells. And, brain cells are damaged when someone either falls and hits their head and the brain smashes against the skull or even when someone doesn't hit their head but their skull is jolted forward and backward, sort of a whiplash action. And, it's that crashing of the brain within the skull that causes the damage to the cells near where the contact is made.
Sometimes these cells are damaged by the shearing forces of the brain rotating within the skull and it tears and shears these neurons or brain cells as well. But by definition if you have a concussion, you've had a brain injury. And, it's very important not to minimize the effects or the potential long lasting consequences of a concussion. You need to see a doctor and get it evaluated properly. The odds are that people will recover with a concussion but some don't, and it's important to have it diagnosed early.