Overview of head injuries

[Marquetta]

Common causes of head injuries include falls, motor vehicle crashes, assaults, and mishaps during sports and recreational activities.
People with minor head injuries may have a headache or dizziness.
People with more severe head injuries may lose consciousness or have symptoms of brain dysfunction.
Computed tomography is used to check for severe head injuries.
Treatment of people with severe head injuries aims to ensure that the brain gets sufficient oxygen and that pressure in the brain remains normal.

The thick, hard bones of the skull help protect the brain from injury. Also, the brain is surrounded by layers of tissue (meninges) containing cerebrospinal fluid, which cushions the brain. Consequently, most bumps and knocks on the head do not injure the brain. Head injuries that do not affect the brain are considered minor.
Head injuries may cause brain injury (traumatic brain injury, or TBI).
In the United States, about 50 in 10,000 people have a head injury each year. In 2014, TBIs contributed to

About 2.5 million emergency department visits
About 288,000 people being hospitalized
About 56,800 deaths

TBIs contribute to about 30% of all deaths caused by injuries of any kind. About 25 to 33% of people in the United States who have a severe head injury die. About 5.3 million people have permanent disabilities due to head injury.
Head injuries include the following:

Injury to the scalp
Skull fractures
Concussions, often sports-related
Bruises (contusions) and tears (lacerations) in the brain
Accumulation of blood within the brain or between the brain and skull (intracranial hematoma)
Damage to nerve cells throughout the brain (diffuse axonal injury)
Bleeding between the layers that cover the brain (such as a subarachnoid hemorrhage)

The brain may not be damaged even when external injuries are severe.