What is a head injury?

A head injury is a broad term that describes many injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the head. Head injuries are also commonly referred to as brain injury, or traumatic brain injury (TBI), depending on the extent of the head trauma.

Head injuries are one of the most common causes of disability and death in adults. The injury can be as mild as a bump, bruise (contusion), or cut on the head. Or it can be moderate to severe in nature due to a concussion, deep cut or open wound, fractured skull bone(s), or from internal bleeding and damage to the brain.

These are some of the different types of head injuries:

• Concussion. A concussion is an injury to the head area that may cause instant loss of awareness or alertness for a few minutes up to a few hours after the traumatic event.

• Skull fracture. A skull fracture is a break in the skull bone. There are four major types of skull fractures:

  • Linear skull fractures. This is the most common type of skull fracture. In a linear fracture, there is a break in the bone. But it does not move the bone. For this type of fracture, your healthcare provider may observe you in the hospital for a brief time. Usually, you will not need treatment and you can resume normal activities in a few days.

  • Depressed skull fractures. You may or may not have a cut in the scalp with this type of fracture. In this fracture, part of the skull is actually sunken in from the trauma. This type of skull fracture may need surgery, depending on the severity, to help correct the deformity.

  • Diastatic skull fractures. These fractures occur along the suture lines in the skull. The sutures are the areas between the bones in the head that fuse during childhood. In this type of fracture, the normal suture lines are widened. Newborns and older infants are more likely to get these types of fractures.

  • Basilar skull fracture. This is the most serious type of skull fracture. It involves a break in the bone at the base of the skull. With this type of fracture, you may have bruises around the eyes and a bruise behind the ear. You may also have clear fluid draining from the nose or ears due to a tear in part of the covering of the brain. If you have this type of fracture, you will need close observation in the hospital.

• Intracranial hematoma (ICH). An intracranial hematoma is a blood clot in or around the brain. There are different types of hematomas. They are classified by their location in the brain. These can cause mild head injuries to quite serious and potentially life-threatening injuries. The different types of intracranial hematomas include:

  • Epidural hematoma. Epidural hematomas occur when a blood clot forms underneath the skull, but on top of the tough covering that surrounds the brain (the dura). They usually come from a tear in an artery that runs just under the skull. Epidural hematomas are usually associated with a skull fracture.

  • Subdural hematoma. Subdural hematomas occur when a blood clot forms underneath the skull and underneath the dura, but outside of the brain. These can form from a tear in the veins that go from the brain to the dura, or from a cut on the brain itself. They are sometimes, but not always, associated with a skull fracture.

  • Contusion or intracerebral hematoma. A contusion is a bruise to the brain itself. A contusion causes bleeding and swelling inside of the brain around the area where the head was struck. Contusions may occur along with a fracture or other blood clots.

• Subarachnoid hemorrhage. This is when there is bleeding into the cerebrospinal fluid (CSF), the fluid that covers the brain. It is often linked with a subdural hemorrhage or contusion.

• Diffuse axonal injury (DAI). These injuries are common and are usually caused by shaking of the brain back and forth, which can happen in car accidents, from falls, or abusive head trauma (sometimes called shaken baby syndrome). Diffuse injuries can be mild, such as with a concussion, or may be very severe, as in diffuse axonal injury. If severe, you may be in a coma for a prolonged period or indefinitely, with injury (microhemorrhages) to many different parts of the brain.

• Penetrating injuries. These can result from bullets or other projectiles.

What causes a head injury?

There are many causes of head injury in children and adults. The most common traumatic injuries are from motor vehicle accidents (cars, motorcycles, or struck as a pedestrian), violence, falls, or child abuse. Subdural hematomas and brain hemorrhages can sometimes happen spontaneously. The most common causes of head injury depend on age. Older adults tend to be at risk from falls, while younger people may be more at risk from contact sports, motor vehicle accidents, or violence.

When there is a direct blow to the head, shaking of the child, or when a whiplash-type injury occurs, the brain jolts backwards and hits the skull on the opposite side, causing a bruise. The jarring of the brain against the sides of the skull can cause tearing of the internal lining, tissues, and blood vessels that may result in internal bleeding, bruising, or swelling of the brain.

Who is at risk for a head injury?

Young children, older adults, and males are most at risk for head injuries. Those who don’t use child car seats, seat belts, or safety helmets are also at increased risk for head injuries. People under the influence of alcohol or drugs are more likely to have a head injury.

What are the symptoms of a head injury?

Symptoms vary depending on the severity of the head injury. These are the most common symptoms of a head injury.

How is a head injury diagnosed?

The full extent of the head injury may not be completely understood immediately after the injury. You will need comprehensive evaluation and testing. A physical exam and other tests help make the diagnosis of a head injury. During the exam, the healthcare provider will ask about your medical history and how you were injured. Trauma to the head can cause neurological problems and may need further medical follow up.

Diagnostic tests may include:

• Blood tests.

• X-ray. This test uses electromagnetic energy beams to make images of internal tissues, bones, and organs onto film.

• CT scan. This procedure uses a combination of X-rays and a computer to make detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

• Electroencephalogram (EEG). This procedure records the brain's continuous, electrical activity by means of electrodes attached to the scalp.

• MRI. This test uses large magnets, radio waves, and a computer to make detailed images of organs and structures in the body. It does not use X-rays.

How is a head injury treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how bad the condition is.

Depending on the severity of the injury, treatment may range from ice and rest to observation to surgery.

For a severe head injury, you are watched for increased intracranial pressure (pressure inside the skull). Head injury may cause the brain to swell. Since the brain is covered by the skull, there is only a small amount of room for it to swell. This causes pressure inside the skull to increase, which can lead to brain damage.

Intracranial pressure is measured in one of two ways. 

• One way is to place a small hollow tube (catheter) into the fluid-filled space in the brain (ventricle).

• The second way is to use a small, hollow device (bolt) placed through the skull into the space just between the skull and the brain.

Your healthcare provider will insert one or both devices in the intensive care unit (ICU) or in the operating room. They will then attach the device to a monitor that gives a constant reading of the pressure inside the skull. If the pressure goes up, it can be treated right away. While the device is in place, you will be given medicine to stay comfortable. Your healthcare provider will remove the device when the swelling has gone down and there is little chance of more swelling.

What are possible complications of a head injury?

A head injury can result in loss of muscle strength, fine motor skills, speech, vision, hearing, or taste function, depending on the brain region involved and the severity of brain damage. Long- or short-term changes in personality or behavior may also occur. You may need long-term medical and rehabilitative (physical, occupational, or speech therapy) management.

What can I do to prevent a head injury?

The key to head injury prevention is to promote a safe environment for children and adults and to prevent head injuries from occurring in the first place. The following measures can help prevent head injury:

• Use car seats and seat belts when riding in the car and helmets (when worn correctly) for activities, such as bicycle riding, in-line skating, skiing, skateboarding, and other sports.

• Prevent falls. Since older adults are prone to falls, it is important to make their living areas safe by removing throw rugs or clutter that may cause them to trip. Install handrails in the bathroom and stairways, and be sure that there is good lighting.

• For young children, it is important to secure windows with window guards and safety gates.

When should I call my healthcare provider?

Seek medical attention right away if any of these occur:

• A cut (laceration)

• Persistent or increasing sleepiness or confusion

• Seizure, repeated vomiting, or severe headache

• Inability to feel an arm or leg or recognize people

• Loss of balance

• Difficulty speaking, seeing, or breathing

• Loss of consciousness

Key points about head injury

• A head injury is a broad term that describes many injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the head.

• The most common traumatic injuries are from motor vehicle accidents, violence, falls, or child abuse.

• Moderate to severe head injury needs immediate medical attention.

• Severe head injury needs close monitoring for increased intracranial pressure.

• Prevention is most important. Promote a safe environment for children and adults through the use of car seats, seat belts, and helmets. Also remove tripping and fall hazards in the home.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions.