The National Institute for Health and Clinical Excellence (NICE) defines a head injury as any trauma to the head other than shallow injuries on the surface of the face.
For most people, a head injury is usually minor and will not result in any permanent damage. The symptoms are usually mild and short lived.
A minor head injury may cause:
- a bump or bruise on the head
- nausea (feeling sick)
- dizziness
Glasgow Coma Scale
Head injuries are assessed by healthcare professionals using the Glasgow Coma Scale (GCS, see below). This is a scale from 3 to 15 that healthcare professionals use to identify the seriousness of a head injury and how severely the brain has been damaged.
A score of 15 means that there is likely to be little or no damage to the brain. A score lower than 15 means that there may be some degree of damage. The lowest possible score is 3, which means that someone is unconscious and cannot respond at all.
According to the GCS, a head injury is minor if the score is 13, 14 or 15. However, even a minor head injury can require treatment in hospital.
If there is any change to a person’s level of consciousness, for example if they seem confused or cannot remember the accident, this should be treated as a severe head injury. For more information, see Severe head injury.
How common are head injuries?
Each year in England and Wales, around 700,000 people attend accident and emergency (A&E) departments with a head injury. Of these, 90% have only a minor head injury.
The most common causes of head injuries are falls, assaults and road traffic accidents. In the UK, 40-50% of people with head injuries are children. Children may be more likely to have a minor head injury because they have high energy levels and little sense of danger.
Outlook
Minor head injures should not require treatment. However, the person with the injury should be monitored for 48 hours to check for any changes in their condition.
Serious complications from a minor head injury are rare. One study of 200,000 children in England found that only 14 with minor head injuries required neurosurgery (surgery on the bran, spinal cord or nerves).
Other possible complications include long-term headaches, memory loss or difficulty concentrating. One large study that was carried out in the UK found that approximately one in seven people may still experience these symptoms six weeks after a minor head injury.
The rate of death after a head injury is 0.2%. This means that for every 1,000 people who attend an emergency department at a hospital with a head injury, two of them may die. However, most of these deaths are among people with a moderate or severe head injury, rather than a minor head injury.
If you have a head injury, it could affect your ability to drive. It is your legal obligation to inform the Driver and Vehicle Licensing Agency (DVLA) about any medical condition that could have an impact on your driving ability. Go to the Directgov website to find out how to tell the DVLA about a medical condition.