Damage to the scalp, skull, or brain that can vary in severity from minor to life-threatening
- More common under the age of 35
- More common in males
- Drinking alcohol and certain sports are risk factors
- Genetics is not a significant factor
Many people sustain a head injury at some time in their lives, but most are minor with no long-term consequences. For example, from time to time most children fall over and bump their heads. However, head injuries can be serious and are a major cause of death in young men. More than 238,000 people attended hospital in England in 2007/2008 as a result of a head injury. Falls, assaults, and road traffic accidents are the most common causes.
The severity of a head injury should not be judged simply by appearance because serious brain damage can occur with no sign of damage to the scalp or skull.
What are the types?
Head injuries vary in severity and can involve damage to the scalp, skull, or brain, or a combination of all three. In some head injuries, the eyes may also be damaged (see Eye injuries).
Scalp injuries alone are usually minor and have no long-term harmful consequences. However, a small cut to the scalp may result in profuse bleeding because many of the blood vessels are close to the skin surface. As a result, the injury often appears worse than it is.
Fractures of the skull may result from a blow to the head. There may be no bleeding from the scalp, but fractures are sometimes associated with bleeding inside the skull or damage to the brain.
The brain can be damaged directly or indirectly. Direct damage usually occurs in conjunction with a skull fracture or after a penetrating injury, such as a stab wound. Indirect damage tends to occur as a result of a hard blow to the head that does not damage the skull. For example, if the head is struck on one side, the brain can be bruised as it is shaken violently within the skull. The brain may also be damaged by pressure inside the skull caused by a build-up of fluid in the brain after an injury. Bleeding between the membranes that cover the brain (see Subdural haemorrhage) may also cause dangerous compression of brain tissue.
What are the symptoms?
Initial symptoms often develop soon after a head injury and, in minor cases, usually include a mild headache and a lump, bruise, or cut on the scalp. However, an injured person may appear well at first, and then symptoms that can be indications of a more serious head injury develop hours or even days later.
These symptoms include:
Blurred or double vision.
Headache accompanied by nausea and vomiting.
Blood or clear fluid leaking from the nose or ears.
Confusion or drowsiness.
Loss of consciousness.
In severe cases, the person may be persis-tently unconscious (see Coma). Sometimes, a very serious head injury is immediately fatal.
If you have a severe headache or a cut that requires stitches or if additional symptoms develop, you must go to hospital or get medical help at once.
A very young child who is unable to describe his or her symptoms should be watched closely after a head injury. If the child vomits or becomes distressed or drowsy, you should seek medical attention immediately. A head injury that causes loss of consciousness should be assessed in hospital without delay.
Are there complications?
Following a head injury, a few people develop long-term problems that continue for several months or more. These problems include frequent headaches, dizziness, poor concentration, and loss of balance. Persistent ringing in the ears (see Tinnitus) may also develop. People such as boxers who sustain repeated head injuries may eventually develop parkinsonism (see Parkinson’s disease and parkinsonism).
If a head injury results in an open wound, bacteria can enter the skull and cause an infection (see Brain abscess). Rarely, brain damage may affect speech, movement, or mental ability. Some injuries may result in recurrent seizures (see Epilepsy).
What can I do?
If you have sustained a blow to the head but have not lost consciousness and have only a mild headache, it is safe to take paracetamol (see Painkillers) to relieve the pain. However, painkillers such as aspirin and other nonsteroidal anti-inflammatory drugs should not be taken because they may make bleeding worse.
If you are with someone who has a head injury, you should try to control bleeding by pressing a clean pad firmly over the wound. If the person has lost consciousness, however briefly, or if you are concerned about the severity of the injury, you should seek medical advice immediately.
What might the doctor do?
Your doctor will examine you and, if necessary, will arrange for you to have tests at a hospital. These may include X-rays to look for a fracture and MRI or CT scanning to look for swelling or bleeding. You may also need to be admitted to hospital overnight for observation.
If you have a minor injury, your doctor may advise you to rest at home. However, you must seek medical attention if further symptoms develop. A person with a severe head injury is usually admitted to an intensive therapy unit, where continuous monitoring can be carried out. If there is swelling of the brain, corticosteroids may be given. Antibiotics are given if there is a risk of infection. Surgery may be needed to relieve pressure on the brain caused by a build-up of fluid or from the skull pressing on it. You may also need surgery to remove a blood clot.
What is the prognosis?
Most people with a minor head injury recover completely within a few days. The outcome of a serious head injury is often difficult to predict. About 1 in 2 people survives such an injury, although recovery may take up to 2 years, and some impairment, such as speech problems, may remain. In the most severe cases of head injury, there may be paralysis, coma, persistent loss of consciousness (see Persistent vegetative state), or death.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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