What Is It?
Head injury includes several medical problems that are caused by trauma to the head. Some of these problems result from a direct impact to a part of the skull or brain. Others happen indirectly during an injury; when blood vessels stretch and tear, the brain bounces against the inside wall of the skull, or the brain swells because of injury-related chemical changes.
The various types of head injuries include:
- Skull fracture — A skull fracture is a crack or break in one of the skull’s bones. If the skull is dented inward so that fragments of shattered bone are pressed against the surface of the brain, this is called a depressed skull fracture. In most cases, a skull fracture causes a bruise (contusion) on the surface of the brain under the fracture.
- Epidural hematoma — This is a very serious form of bleeding that can occur when one of the blood vessels under the skull is torn during a traumatic injury. Usually the skull is fractured as well. As the injured vessel bleeds, a collection of blood, called a hematoma, forms in the space between the inner surface of the skull and the dura, the outermost of the three membranes that cover the brain. The resulting epidural (outside the dura) hematoma can expand within the skull and press downward on the brain, causing death.
- Acute subdural hematoma — In this injury, a blood vessel tears, and blood collects between the dura and the surface of the brain. This can occur because of an impact, or when the head moves violently forward and back (whiplash) because of a sudden stop. A brain injury from whiplash is most common in the elderly and in people taking blood-thinning medications. Acute subdural hematoma develops rapidly, most commonly after serious head trauma caused by an assault, car accident or fall. It is a very severe brain injury that typically causes unconsciousness, and it is fatal in about 50 percent of cases. Acute subdural hematomas occur in 20 percent to 40 percent of people whose head injuries are described as severe.
- Chronic subdural hematoma — Unlike the acute form, this type of subdural hematoma usually develops over a prolonged period because the bleeding inside the skull is less dramatic. A chronic subdural hematoma typically follows a fairly minor Head injury in a person who is elderly, who is taking blood-thinning medications or whose brain has shrunk as a result of alcoholism or dementia. Symptoms occur gradually over a period of one to six weeks. The most common symptoms are drowsiness, inattentiveness or confusion, headaches, changes in personality, seizures and mild paralysis.
- Intraparenchymal hemorrhages and contusions — Intraparenchymal hemorrhages (bleeding) and contusions (bruising) occur within the brain itself rather than between the brain and the skull. Both of these injuries can be caused by either a direct impact to the brain or an indirect injury, in which the force of an impact on one side of the brain causes the brain to bounce or ricochet within the skull. This produces a second area of damage on the side of the brain opposite the original impact.
Besides the immediate injuries listed above, head trauma also can produce swelling inside the brain and a potentially deadly increase in pressure inside the skull. Head injury also can cause serious damage to brain cells (neurons). In some cases, these cells are destroyed immediately by the impact of a Head injury. In other cases, the damaged neurons take longer to wither and die.
Each year, head injuries result in more than 2 million emergency department visits in the United States, with more than 72,000 deaths. An additional 80,000 to 210,000 people with moderate or severe head injuries become disabled or require extended hospital care. Overall, traumatic head injuries are the most common cause of death among Americans age 45 and younger. In addition, head injuries resulting from falls are a very common cause of hospitalization and death among people over the age of 75. Men are three to four times more likely to sustain head injuries than women, and alcohol use is involved in about 50 percent of cases.
Currently in the United States, the most common causes of closed head injuries, as opposed to open injuries, such as gunshot wounds, are motor vehicle accidents, falls and violent assaults. Because of the extreme forces involved in these types of trauma, up to 75 percent of people with severe head injuries also suffer serious damage to the neck bones or to major organs in other parts of the body. These additional injuries often increase the person’s risk of blood loss, breathing difficulties, very low blood pressure (hypotension) and other problems that can worsen the damage caused by the brain injury alone.
Head injuries can cause a wide variety of symptoms, depending on the specific type of injury, its severity and its location. Some doctors classify head injuries into three categories, based on symptom severity:
- Mild Head injury — There is minimal injury to the outside of the head with no loss of consciousness. The injured person may vomit once or twice and complain of a headache.
- Moderate Head injury — There is a more obvious injury to the outside of the head, and the person may have lost consciousness briefly. Other symptoms can include memory loss (amnesia), headache, dizziness, drowsiness, nausea and vomiting, confusion, a bruise-like discoloration around the eyes or behind the ear, or a clear fluid oozing from the nose (this fluid is not mucus, but fluid from around the brain (cerebrospinal fluid) that has leaked through a skull fracture near the nose).
- Severe Head injury — There is serious damage to the outside of the head, often together with injuries involving the neck, the arms or legs, or major body organs. In most cases, the person is either unconscious or barely responsive. However, some people become agitated or physically aggressive. About 10 percent of those affected have seizures.
All head injuries should be evaluated promptly by a doctor, so either call for emergency help or have a friend or family member drive you to an emergency department. Once you arrive at the emergency department, the doctor will want to know:
- How you hurt your head, including the height of your fall or your position (front seat, back seat, driver) in a car accident
- Your immediate reaction to the injury, especially any loss of consciousness or memory loss
- Any symptoms that occurred soon after the injury, such as vomiting, headache, confusion, sleepiness or seizures
- Your current medications, including alcohol and nonprescription drugs
- Your past medical history, especially any neurological problems (stroke, epilepsy, etc.) and any prior episodes of Head injury
- Whether you are having pain in your neck, chest, abdomen, arms or legs
If you are not able to answer these questions, the information can be provided by a family member, friend or the emergency medical personnel who brought you to the hospital. The doctor’s questions will be followed by a thorough physical and neurological examination, including assessments of your pupil size, reflexes, sensation and muscle strength. If the results of these exams are normal, further tests may not be necessary. However, the doctor may decide to monitor your condition in the hospital.
For someone with more severe head injuries, the first goal of emergency personnel is to stabilize the person’s condition as much as possible before arrival at the hospital. This may involve passing a tube down the throat to assist breathing with a mechanical ventilator, controlling any bleeding from open wounds, maintaining blood pressure with intravenous (injected into a vein) medication and immobilizing the neck in case of a cervical fracture. Once the injured person arrives at the hospital and is stabilized, the doctor will perform a brief physical and neurological evaluation. This will be followed by a computed tomography (CT) scan of the head and spinal X-rays, if necessary. In most cases, a CT scan is the best way to detect skull fractures, brain injury or bleeding inside the head.
Even if your Head injury is only mild, you may have difficulty concentrating temporarily, and may experience occasional headaches, dizziness and fatigue. This collection of symptoms, called postconcussion syndrome, usually improves within three months.
More severe forms of Head injury can be fatal. Those that are not fatal sometimes require an extended hospital stay with prolonged rehabilitation. According to one large study, the average length of stay in a rehabilitation facility was 61 days. In some cases, disability is permanent.
To help prevent head injuries, try the following suggestions:
- If you drink alcohol, drink in moderation. Never drink and drive.
- Protect yourself from vehicle-related head trauma by wearing a seat belt or helmet.
- If you play sports, wear appropriate protective headgear.
- If your job involves working high above the ground, use approved safety equipment to prevent accidental falls. Never work in a high place if you feel dizzy or light-headed, have been drinking alcohol, or are taking medication that can make you dizzy or affect your balance.
- Have your vision checked at least once a year; poor vision can increase your risk of falls and other types of accidents. This is especially true if you are elderly or if you work in high places.
If you have minor head trauma, your doctor may decide to monitor your condition in the emergency department for a short period of time, or to admit you to the hospital for a brief period of observation. While you are in the emergency department or in your hospital room, medical personnel will ask you periodically about your symptoms, check your vital signs, and confirm that you are awake and can respond. Once your doctor is satisfied that you can be sent home safely, he or she will allow you to leave on the condition that a responsible adult will stay with you at home for a day or two to help monitor your condition. This person will be given specific instructions about possible danger signs to watch for.
If you are troubled by headaches after your Head injury, your doctor may suggest that you try acetaminophen (Tylenol) first. If this does not work, your doctor probably will prescribe a more potent pain reliever. Avoid taking aspirin, ibuprofen (Advil, Motrin), naproxen (Naprosyn) or indomethacin (Indocin) during your recovery period since these drugs can increase the risk of bleeding inside the head.
In people with more extensive head injuries, treatment depends on the type of injury, its severity and its location. In many cases, treatment takes place in an intensive-care unit with mechanical ventilation (breathing assistance), and with medications to control pain, decrease swelling inside the brain, maintain blood pressure and prevent seizures. Surgery may be performed to repair a depressed skull fracture, drain an epidural or subdural hematoma, or treat a brain hemorrhage or contusion.
When To Call A Professional
Call for emergency help immediately if you find someone unconscious at an accident scene. Also call for emergency help if someone with a serious Head injury experiences any of the following symptoms:
- Nausea and vomiting
- Difficulty walking
- Slurred speech
- Memory loss
- Poor coordination
- Irrational behavior
- Aggressive behavior
- Numbness or paralysis in any part of the body
Even if someone’s Head injury appears to be less severe, and the symptoms are mild, it may be possible that the person has had significant damage to the brain or its surrounding structures. This is especially true if the injured person:
- Is elderly
- Takes medication to thin the blood
- Has a bleeding disorder
- Has a history of heavy alcohol use
If the injured person has one or more of the risk factors listed above, call a doctor or go to an emergency department immediately.
The prognosis depends on the severity of the injury:
- Mild head injuries — The prognosis is usually very good. Although some people experience postconcussion syndrome, this typically goes away after about three months. In most cases, there is no long-term damage, although improvement may be gradual.
- Moderate head injuries — The most dramatic improvement usually occurs within the first one to six weeks. After that time, there may be some remaining problems with memory or attention, but these may not be permanent.
- Severe head injuries — Up to 50 percent of severe head injuries are fatal. Among people who survive these injuries, about 20 percent suffer severe disabilities.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.