A head injury is any trauma that leads to injury of the scalp, skull, or brain. The injuries can range from a minor bump on the skull to serious brain injury.

Head injury is classified as either closed or open (penetrating).

• A closed head injury means you received a hard blow to the head from striking an object, but the object did not break the skull.
• An open, or penetrating, head injury means you were hit with an object that broke the skull and entered the brain. This usually happens when you move at high speed, such as going through the windshield during a car accident. It can also happen from a gunshot to the head.

There are several types of brain injuries, including:

• Concussion, the most common type of traumatic brain injury, in which the brain is shaken
• Contusion, which is a bruise on the brain

See also:

• Subarachnoid hemorrhage
• Subdural hematoma

Every year, millions of people have a head injury. Most of these injuries are minor because the skull provides the brain with considerable protection. The symptoms of minor head injuries usually go away on their own. More than half a million head injuries a year, however, are severe enough to require hospitalization.

Learning to recognize a serious head injury, and implementing basic first aid, can make the difference in saving someone's life.

In patients who have suffered a severe head injury, there are often other organ systems injured. For example, a head injury is sometimes accompanied by a spinal injury.

Common causes of head injury include traffic accidents, falls, physical assault, and accidents at home, work, outdoors, or while playing sports.

Some head injuries result in prolonged or non-reversible brain damage. This can occur as a result of bleeding inside the brain or forces that damage the brain directly. These more serious head injuries may cause:

• Coma
• Chronic headaches
• Loss of or change in sensation, hearing, vision, taste, or smell
• Paralysis
• Seizures
• Speech and language problems

The symptoms of a head injury can occur immediately or develop slowly over several hours or days. Even if the skull is not fractured, the brain can bang against the inside of the skull and be bruised. The head may look fine, but complications could result from bleeding or swelling inside the skull.

When encountering a person who just had a head injury, try to find out what happened. If he or she cannot tell you, look for clues and ask witnesses. In any serious head trauma, always assume the spinal cord is also injured.

The following symptoms suggest a more serious head injury -- other than a concussion or contusion -- and require emergency medical treatment:

• Changes in, or unequal size of pupils
• Convulsions
• Distorted features of the face
• Fluid draining from nose, mouth, or ears (may be clear or bloody)
• Fracture in the skull or face, bruising of the face, swelling at the site of the injury, or scalp wound
• Impaired hearing, smell, taste, or vision
• Inability to move one or more limbs
• Irritability (especially in children), personality changes, or unusual behavior
• Loss of consciousness, confusion, or drowsiness
• Low breathing rate or drop in blood pressure
• Restlessness, clumsiness, or lack of coordination
• Severe headache
• Slurred speech or blurred vision
• Stiff neck or vomiting
• Symptoms improve, and then suddenly get worse (change in consciousness)

Get medical help immediately if the person:

• Becomes unusually drowsy
• Behaves abnormally
• Develops a severe headache or stiff neck
• Loses consciousness, even briefly
• Vomits more than once

For a moderate to severe head injury, take the following steps:

1. Call 911.
2. Check the person's airway, breathing, and circulation. If necessary, begin rescue breathing and CPR.
3. If the person's breathing and heart rate are normal but the person is unconscious, treat as if there is a spinal injury. Stabilize the head and neck by placing your hands on both sides of the person's head, keeping the head in line with the spine and preventing movement. Wait for medical help.
4. Stop any bleeding by firmly pressing a clean cloth on the wound. If the injury is serious, be careful not to move the person's head. If blood soaks through the cloth, DO NOT remove it. Place another cloth over the first one.
5. If you suspect a skull fracture, DO NOT apply direct pressure to the bleeding site, and DO NOT remove any debris from the wound. Cover the wound with sterile gauze dressing.
6. If the person is vomiting, roll the head, neck, and body as one unit to prevent choking. This still protects the spine, which you must always assume is injured in the case of a head injury. (Children often vomit ONCE after a head injury. This may not be a problem, but call a doctor for further guidance.)
7. Apply ice packs to swollen areas.

For a mild head injury, no specific treatment may be needed. However, closely watch the person for any concerning symptoms over the next 24 hours. The symptoms of a serious head injury can be delayed. While the person is sleeping, wake him or her every 2 to 3 hours and ask simple questions to check alertness, such as "What is your name?"

If a child begins to play or run immediately after getting a bump on the head, serious injury is unlikely. However, as with anyone with a head injury, closely watch the child for 24 hours after the incident.

Over-the-counter pain medicine, such as acetaminophen, may be used for a mild headache. DO NOT take aspirin, ibuprofen, or other anti-inflammatory medications because they can increase the risk of bleeding.

• DO NOT wash a head wound that is deep or bleeding a lot.
• DO NOT remove any object sticking out of a wound.
• DO NOT move the person unless absolutely necessary.
• DO NOT shake the person if he or she seems dazed.
• DO NOT remove a helmet if you suspect a serious head injury.
• DO NOT pick up a fallen child with any sign of head injury.
• DO NOT drink alcohol within 48 hours of a serious head injury.

Call 911 if:

• There is severe head or facial bleeding
• The person is confused, drowsy, lethargic, or unconscious
• The person stops breathing
• You suspect a serious head or neck injury or the person develops any signs or symptoms of a serious head injury

• Always use safety equipment during activities that could result in head injury. These include seat belts, bicycle or motorcycle helmets, and hard hats.
• Obey traffic signals when riding a bicycle. Be predictable so that other drivers will be able to determine your course.
• Be visible. DO NOT ride a bicycle at night unless you wear bright, reflective clothing and have proper headlamps and flashers.
• Use age-appropriate car seats or boosters for babies and young children.
• Make sure that children have a safe area in which to play.
• Supervise children of any age.
• DO NOT drink and drive, and DO NOT allow yourself to be driven by someone who you know or suspect has been drinking alcohol or is otherwise impaired.

Heegaard WG, Biros MH. Head. In: Marx J. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. St. Louis, Mo: Mosby; 2006: chap. 38.

Atabaki SM. Pediatric head injury. Pediatr Rev. 2007 Jun;28(6):215-24.