Head injury primarily affects young adults between 15 and 44 years of age. Males are affected more than twice as often as females. There is no difference in incidence between whites and nonwhites in the United States. Patients involved in motor vehicle accidents also have multiple other injuries, and are in the 15 to 24 year age group. Other causes include assault with injury to the head, motorcycle and bike related injuries, and penetrating injuries including stab wounds with a knife or ice pick and gun shot wounds to the head.
Falls occur in children and usually result in less severe injuries.
The month of April has an early peak occurrence followed by the highest peak in September. Fridays, Saturdays and Sundays are the most common days of the week when these injuries occur. Most often head injury occurs in combination with spinal cord injury. Head injury ranges from the mild to moderate and severe categories. Most often patients recover completely with no deficits.