There are many causes of head injury in children and adults. The most common traumatic injuries are from motor vehicle accidents (automobiles, 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 cause internal bleeding, bruising, or swelling of the brain.

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.

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

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 require 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.

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe 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 monitored 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.

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.

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.