Severe head injuries require immediate medical attention because there's a risk of serious brain damage.

Signs of a severe head injury can include:

  • unconsciousness – either brief (concussion) or for a longer period of time
  • fits or seizures 
  • difficulty speaking or staying awake
  • problems with the senses such as hearing loss or double vision
  • repeated vomiting
  • blood or clear fluid coming from the ears or nose
  • memory loss (amnesia)

If you experience any of these symptoms after a head injury, go immediately to your nearest accident and emergency (A&E) department or call 999 and ask for an ambulance.

Read more about the symptoms of a severe head injury.

Diagnosing a severe head injury

Healthcare professionals use the Glasgow Coma Scale (GCS) to assess head injuries. This is a scale from 3 to 15 that identifies how serious your head injury is, based on your symptoms, and whether the brain has been damaged (with 3 being most severe and 15 least severe).

A head injury is usually classed as being moderate if someone has a GCS score of 9-12 or severe if they have a score of eight or lower. Some people with significant head injuries have a high GCS score initially, but their score decreases when they're reassessed at a later stage.

Further tests, such as a computerised tomography (CT) scan, are sometimes needed to determine the seriousness of a head injury.

Read more about how severe head injuries are diagnosed.

Treating a severe head injury

Severe head injuries always require treatment in hospital. Hospital treatment may involve:

  • observing the condition for any changes
  • running tests to check for further damage
  • treating any other injuries
  • breathing support (ventilation) or brain surgery, in the most severe cases

Most people are able to go home within 48 hours. However, a small number of those admitted to hospital require skull or brain surgery.

When you're discharged from hospital, your doctor will give you advice about the best way to help your recovery when you return home.

Read more about how a severe head injury is treated and recovering from a severe head injury.


A severe head injury may cause a build-up of pressure on the brain because of bleeding, blood clots or a build-up of fluid. This can sometimes lead to brain damage, which can be temporary or permanent.

A severe head injury can also cause other potentially serious complications including:

  • an infection after a skull fracture
  • post-concussion syndrome – where you experience long-term symptoms after sustaining concussion
  • impaired consciousness
  • brain injury

Around one in every 2,000 people who attend an A&E department with a head injury dies as a result of their injury.

Read more about complications after a severe head injury.

Preventing head injuries

It can be difficult to predict or avoid a head injury, but there are some things you can do to reduce the risk of serious injury to you or your child. These include:

  • reducing hazards in the home that may cause a fall
  • 'childproofing' your home
  • using the correct safety equipment for work, sport and DIY

Wearing a safety helmet during certain activities, such as skiing or cycling, may also help prevent a serious head injury.

Read more about how to prevent head injuries.

Page last reviewed: 28/09/2015

Next review due: 28/09/2017