Complications of a severe head injury 

Severe head injuries can cause serious complications. This is mainly because a serious injury can damage the brain, sometimes permanently.

In particularly severe cases, a serious head injury can be fatal. People with these type of injuries are closely monitored when they're admitted to hospital to ensure any complications that arise are dealt with promptly and effectively.


If your skull is fractured during a head injury, your risk of developing an infection may be increased. Skull fractures can occasionally tear the membrane (the thin layer of cells) that surrounds the brain. If this happens, bacteria can enter the wound and cause an infection.

It's important to keep any external wounds on your head clean so they don't become infected. You may also be prescribed antibiotics.

Post-concussion syndrome

Some people may experience long-term symptoms after sustaining concussion from a head injury. This could be post-concussion syndrome.

Symptoms of post-concussion syndrome can include:

  • having trouble looking after yourself
  • not being able to work
  • a persistent headache
  • dizziness
  • feeling weak
  • tinnitus (hearing sounds that come from inside the body, rather than from an outside source)
  • nausea (feeling sick)
  • trouble sleeping and fatigue (extreme tiredness)
  • memory problems 
  • problems understanding other people
  • poor concentration

These symptoms usually clear up in around three months but, if necessary, you may need to be referred for further assessment by your GP. You may be seen by a neurologist, who specialises in problems of the nervous system (brain, spinal cord and nerves), or a psychiatrist (a mental health specialist).

Read more about post-concussion syndrome.

Impaired consciousness

Some people who sustain a severe head injury enter a state of impaired consciousness, such as a coma, vegetative state or minimally conscious state.

These disorders of consciousness affect wakefulness (the ability to open your eyes and have basic reflexes) and awareness (more complex thoughts and actions, such as following instructions, remembering and communicating).

These states sometimes only last a few weeks, after which time a person may wake up or progress into a different state of impaired consciousness. However, they can last years and some people will never regain consciousness.

If a person is in a state of impaired consciousness for a long time, usually at least a year, it may be recommended that nutritional support is withdrawn because there's almost no chance of a recovery by this point.

If agreement is reached about withdrawing life support, the decision has to be referred to the courts in England and Wales before any further action can be taken.

Read more about treating disorders of consciousness.

Brain injury

A severe head injury can damage the brain in several ways. For example, brain damage can occur as a result of increased pressure on the brain caused by a blood clot between the skull and the surface of the brain (subdural haematoma), or bleeding in and around the brain (subarachnoid haemorrhage).

Injuries to the brain can lead to a variety of problems. Some types of brain injury are only temporary, whereas others result in permanent damage. The effect of any brain injury will depend on:

  • whereabouts on the head the injury occurs
  • the type of injury – for example, if the skull is fractured
  • the severity of the injury – for example, if it requires surgery

The different effects of a brain injury are described below.

Physical effects

Physical effects of a brain injury can include difficulty moving or keeping your balance and loss of co-ordination. You may also experience headaches or increased tiredness. 

Hormonal effects

Some head injuries can damage the pituitary gland. The pituitary gland is a pea-sized gland in the centre of the head. It hangs below the brain and produces hormones (powerful chemicals that have a wide range of effects on the body). If the pituitary gland is damaged, it may lead to a reduction in the production of hormones.

Sensory effects

Your senses may be affected by a brain injury. For example, you may lose your sense of taste or smell. You may also notice blind spots in your vision or you may not be able to control your body temperature as well as before, so that you feel too hot or too cold.

Cognitive effects

Following a head injury, your ability to think, process information and solve problems may be affected. You may also experience memory problems, particularly with your short-term memory, and have difficulty with speech and communication skills.

Emotional or behavioural effects

After a severe head injury, you may experience changes to your feelings and behaviour. For example, you may have feelings of irritation, anger or selfishness.

You may be less sensitive to other people’s feelings, or lose your inhibitions and behave in a way other people may consider inappropriate. You may also laugh or cry more than you did before the injury.

Getting support

As every brain injury is different, it's a good idea to seek further information about the possible effects and rehabilitation techniques. A number of charities and organisations may be able to help, including:

Chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a condition that can occur if a person receives repeated blows to their head over a long period of time.

In CTE, the nerve cells in the brain become gradually damaged, causing symptoms such as memory loss, confusion, poor judgement, aggression and depression. Eventually, CTE can lead to progressive dementia.

Physical problems, such as tremor, loss of muscle function and difficulty walking, may also occur at a later stage of CTE.

CTE was first observed in boxers and American footballers, but people who play other contact sports, such as rugby, or sports where there's a danger of falling from height, such as horse riding, are also at risk of developing the condition.


Page last reviewed: 28/09/2015

Next review due: 28/09/2017