Severe head injury
Severe head injuries need urgent medical assessment as there’s a risk of serious permanent brain damage.
It can be hard to tell the difference between a minor and a severe head injury.
Read about minor head injuries
Symptoms
The symptoms of a severe head injury can vary from person to person.
Phone 999 if you or someone else has a head injury and:
- is unresponsive to their name or a gentle chest rub
- cannot stay awake
- has had a seizure (fit)
- has fallen from a height like 5 or more stairs
- is having problems with their senses, like hearing loss or double vision
- has numbness or weakness in any part of their body
- is struggling to walk, balance, speak, write, or understand other people
- hit their head with force, like being hit by a car
- has a head wound with something inside it, like glass
- has signs of damage to their skull, like a dent in their head
- has severe neck pain or cannot move their head
Go to A&E if you or someone else has a head injury and:
- is confused or was ‘knocked out’ for any length of time
- has vomited
- has a persistent headache that is not helped by painkillers
- is showing unusual behaviour, like being very irritable or crying more than usual
- has memory loss (amnesia)
- is intoxicated due to alcohol or recreational drugs
- has a blood clotting disorder (haemophilia) or takes blood thinning medicine (like warfarin or apixaban)
- has previously had brain surgery
- has a large bruise or wound to the head or face
- has a black eye
- has blood or clear fluid coming from their ears or nose
- has bruising behind their ears
- the injury wasn’t accidental, for example if someone else has hurt a child on purpose
Diagnosing a severe head injury
A person with a severe head injury should be seen in an A&E (accident and emergency) department.
The healthcare professionals treating you will prioritise any life-threatening injuries. Once you’re in a stable condition, they’ll ask some questions. This can help with the diagnosis and treatment of your injury.
If someone witnessed your accident, it’s helpful for them to come to hospital with you to describe what happened.
Assessing your injuries
A healthcare professional will assess your brain function using the Glasgow Coma Scale (GCS). This is an assessment of how serious your brain injury is. It’s based on your ability to open your eyes, to speak, and to move your body.
You may have a computerised tomography (CT) scan. This produces a detailed image of the inside of your head. This image shows whether there’s any bleeding, bruising or swelling in your brain.
Skull x-rays are not carried out anymore as they do not provide information on brain damage.
If someone is confused, they may struggle to cooperate with a CT scan. In these cases, they may require anaesthesia to allow the scan to happen and to prevent their brain injury from getting worse.
Reduced consciousness
Some people who sustain a severe head injury enter a state of reduced consciousness. Examples of reduced consciousness are confusion, drowsiness and coma.
This can last for a few days, weeks, or years, and can be caused by other things like alcohol or drugs.
It’s possible for someone to partially or fully recover from reduced consciousness, depending on the cause.
If someone is in a state of reduced consciousness, the medical professionals treating them can sometimes give further information on:
- their current state
- how likely they are to recover
Treating a severe head injury
Depending on your specific injury and examination results, you may be:
- admitted to hospital for further testing and treatment
- allowed to go home after examination
- sent home with advice to attend follow-up appointments at your local neurological centre or head injury clinic
Admission to hospital
If you’re admitted to hospital, the treatment you receive will depend on your injuries.
Wounds
Wounds to the head often bleed a lot, especially if you’re taking anti-coagulant medications (like warfarin or apixaban).
Any cuts or grazes to your head will be treated to prevent further bleeding or infection. If there are foreign bodies in the wound, like broken glass, they’ll need to be removed.
Deep or large cuts may need to be closed with glue, stitches or staples until they heal. Local anaesthetic may be used to numb the area around the cut so you don’t feel any pain.
Brain injuries – observation
If you need to be observed, the healthcare professionals treating you will regularly check:
- your level of consciousness and how alert you are (using GCS)
- the size of your pupils and how well they react to light
- how well you can move your arms and legs
- your breathing, heart rate, blood pressure, temperature and the level of oxygen in your blood
This gives medical professionals a bedside assessment of how your brain injury is progressing.
Brain injuries – neurosurgery
Neurosurgery is any type of surgery used to treat nervous system problems (problems with the brain, spinal cord and nerves). The majority of head injuries will heal by themselves and do not benefit from neurosurgery.
If surgery is needed, a neurosurgeon (a specialist in brain surgery) may speak to you or your family first.
However, some problems may require urgent treatment. This means there may not be time to discuss surgery before it’s carried out. In such cases, your surgeon will discuss the surgery with you or your family after the operation.
Someone who has neurosurgery is likely to need close monitoring after their operation, and have a long rehabilitation period.
Skull fractures
Your skull may be fractured during a head injury. Skull x-rays are of very limited value because it gives little information about brain injury. Instead, a CT scan will help determine the extent of the injury.
Most skull fractures will heal by themselves, particularly if they’re simple, linear fractures. The healing process can take many months. You may have a headache for a few weeks. This should be eased with over-the-counter painkillers.
Complications
Because severe head injuries can cause such damage, serious complications can happen. These can sometimes be permanent.
Complications can include:
The brain and its lining can become infected (meningitis). You may be offered a vaccination to prevent this happening.
There are many reasons brain injury can happen. It can be temporary or permanent. The effects of brain injury are difficult to predict, but could include:
- headaches and tiredness
- problems with your memory
- difficulty moving, keeping your balance, or with co-ordination
- loss of your sense of taste smell
- changes in your vision, including blind spots
- difficulty thinking, processing information and solving problems
- difficulty with speech and communication
- changes to your normal feelings and behaviour
- aggression or loss of inhibitions
- epilepsy
Some people experience the symptoms of concussion for a long time after the initial injury. This is called post-concussion syndrome.
Going home
When you’ve recovered enough to go home, you’ll need someone to take you. You should not drive until you’ve completely recovered.
If you’ve been sent home less than 24 hours after your injury happened, you’ll need someone to stay with you until this time has passed. This is to keep an eye out for problems appearing.
You may be advised not to take your blood thinning medication for a short period.
Do not stop taking any medicine that’s been prescribed without checking with your GP or healthcare professional first. You could make yourself very ill.
Follow-up appointments and rehabilitation
You may be advised to see your GP the week after you’re discharged from hospital, so they can check how you’re coping.
You may also have a follow-up appointment at a head injury clinic. This will usually be with a specialist in head injury.
Depending on your injury, you may be offered different treatment to help you recover. This could include:
- physiotherapy, to help with physical problems like weakness, stiffness or poor co-ordination
- occupational therapy, to help you if you’re struggling with everyday tasks
- speech therapy
- psychological therapy, to help you cope if your injury has affected your mental wellbeing
Getting support
Every brain injury is different. It’s a good idea to seek further information about possible effects and rehabilitation techniques. A number of charities and organisations may be able to help, including:
Last updated:
14 July 2025