Brain injury

Diagnosing a severe head injury

Someone with a severe head injury should always be seen in an emergency department.

If any of the symptoms of a severe head injury are present, immediately go to your local accident and emergency (A&E) department or call 999 and ask for an ambulance.

The healthcare professionals treating you will first make sure you are in a stable condition, before asking some questions to help with the diagnosis and treatment of your injury. These may include:

  • how you were injured
  • when you were injured
  • if you have been drinking alcohol
  • if you have taken any illegal drugs

If you cannot remember how the injury occurred, they may ask someone who saw your accident to describe it.

You may also be asked about your symptoms, for example:

  • whether you have lost consciousness
  • whether you have a headache
  • whether you have been sick

If you are with someone who has a head injury, try to provide as much information as possible about the accident and the person’s symptoms.

The paramedics or doctors treating you will assess your condition using the Glasgow Coma Scale (GCS), described below.

Glasgow Coma Scale

After a head injury, healthcare professionals use the Glasgow Coma Scale (GCS) to assess how severely your brain has been damaged. The GCS scores you on:

  • verbal responses (whether you can make any noise)
  • physical movements
  • how easily you can open your eyes

Your score for each of these three areas is added up to give a total. A slightly different version of the GCS is used for children under five years old.

A score of 15 (the highest possible score) means that you know where and who you are, you can speak and move as instructed, and your eyes are open.

A score of three (the lowest possible score) means that you cannot open your eyes and you cannot move or make a noise. The score indicates that your body is in a coma (a state of unconsciousness where a person is unresponsive and cannot be woken).

Depending on your score, head injuries are classed as:

  • minor – a score of 13 or higher
  • moderate – a score of 9-12
  • severe – a score of 8 or lower

Based on your assessment, you may be allowed to go home or you may be referred for further testing and treatment in hospital.

The brain injury association Headway has more detailed information about the Glasgow Coma Scale.

Going home

You will usually only be allowed to go home after a head injury if an assessment suggests that you are at low risk of brain injury and a CT scan is not deemed necessary.

You will need someone to take you home because you will not be allowed to drive until you have completely recovered. If possible, you will also need someone to stay with you for the first 24 hours after your injury to keep an eye out for problems.

The health professionals will advise you about what to do and what not to do in the weeks following your injury. Read about recovering from a head injury for more information about caring for a head injury at home. 

CT scan

Based on the results of their assessment, emergency department staff will decide whether you need to have a computerised tomography (CT) scan to determine how serious your head injury is and whether you are at risk of developing any complications of a severe head injury.

A CT scan involves a series of X-rays being taken of your body from different angles. This produces a detailed image of the inside of your body. The scan can be used to examine the bone, muscle and tissue in your neck, to check for any damage and to identify whether there is any bleeding or swelling in your brain.

Depending on the results of your scan, you may be allowed to go home, but usually you will be kept in hospital for a short time to make certain that your injury has not caused any serious problems.

Admission to hospital

Some people need to be admitted to hospital for observation following a head injury. This may be because:

  • scans have shown a problem
  • you have persistent symptoms of a possible neurological problem (a problem with the nervous system)
  • your GCS score has not returned to 15
  • you have other injuries (such as broken bones) or health problems
  • you are under the influence of alcohol or drugs
  • there is no one at home to look after you

See how a severe head injury is treated for more information about what happens when you are admitted to hospital.



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