In rare cases, a dangerous blood clot may form on the brain in a person with a concussion and crowd the brain against the skull. An athlete should receive immediate medical attention if after a bump, blow, or jolt to the head or body.
If s/he exhibits any of the following danger signs: One pupil larger than the other, Is drowsy or cannot be awakened, A headache that gets worse, Weakness, numbness, or decreased coordination. Repeated vomiting or nausea, Slurred speech, Convulsions or seizures, Cannot recognize people or places ,Becomes increasingly confused, restless, or agitated or Has unusual behavior.