The federal Centers for Disease Control define a traumatic brain injury, or TBI, as a “bump, blow, or jolt to the head” that disrupts normal brain function. This can range from mild to severe—from a bump on the head that raises a knot and gives you a headache up to a head injury that penetrates the skull and causes permanent brain damage. Roughly two million TBIs every year are at least severe enough to get treated or reported.
Doctors categorize the vast majority as “mild,” although some TBIs diagnosed as “mild” cause lifelong disabilities. Severe TBIs can result in catastrophic injuries that result in permanent severe impairment of brain function or even death. The most severe TBIs involve penetration of the skull and often are the result of major traffic accidents. All TBIs—even those considered mild—can have long-term consequences.
