Effects and Symptoms

An injury to the head will nearly always have an impact upon the brain. The brain, through a system of millions of nerves, controls every thought, physical action and emotion. An injury to the head can therefore stop these actions and that is why a brain injury can be so wide ranging in its effect and devastating in its consequences.

How Common is a Brain Injury?

Every year one million people will attend hospital with a brain injury. Fortunately in 85% of cases the injury is mild and in most of these cases with correct medical treatment will go on to make a good recovery within 6 months. If a person losses consciousness for over 6 hours the injury is classed as severe. People with severe brain injuries are likely to have complex problems and will need long term rehabilitation. Somtimes however even mild injuries can cause long lasting impairments.

Missed Diagnosis of a Brain Injury

Unfortunately it is estimated up to 75% of all brain injuries go unreported and unassessed by medical professionals. This is often because there is no loss of consciousness at the time of the injury and symptoms do not become apparent until many days, weeks or months after the accident. Brain injury is frequently misdiagnosed as depression. Often depression is a consequence of a brain injury but sometimes this diagnosis can mask more serious underlying problems.

People with a head injury might experience a number of symptoms that might be overlooked. People with a brain injury often do not have insight into their own problems. They will not be themselves. If you or someone you know has suffered with a traumatic head injury and develops any of the symptoms listed below (however minor), immediate medical advice and possible legal advice should be sought.

The most severe types of head injury can cause extensive functional limitations such a paralysis, and severely limited mental functioning. A little further down the continuum of head injuries you will find moderate head injuries. Moderate head injuries are characterized by corresponding degrees of functional limitations mostly in the form of diminished mental skills. Then on the other end of the continuum you will find what is called concussion, mild or minor head injuries. Like the moderate head injuries, mild head injury can cause impairments in mental functioning. The irony of mild head injuries is that often, such injuries do not even require a hospital stay, yet they result in changes so profound that lives are forever changed. The term mild head injury belies the true nature of the resultant impairments.

Physical impairments

  • Deafness
  • Balance and language problems
  • Visual loss
  • Sensory loss to limbs
  • Difficulty in swallowing
  • Epilepsy


  • Anxiety or depression

Cognitive impairments

  • Thinking
  • Understanding
  • Reasoning
  • Carrying through a thought process
  • No insight into difficulties
  • Problems with concentration
  • Memory loss
  • Poor attention
  • Slow learning

Behavioural problems

  • Mood changes
  • Aggression or violence
  • Anger
  • Social inhibition
  • Tiredness
  • Poor motivation
  • Inappropriate responses or lack of inhibition

The effects of a brain injury can vary from minor to very serious of even fatal. Brain injuries can cause hidden disabilities that can change the personality, thinking and memory of the patient.

Nearly every person who suffers a brain injury will experience a period of confusion and disorientation. They may not be able to remember the incident and may seem confused. This is defined as Post-Traumatic Amnesia (PTA). The length of time the PTA lasts for together with the length of time the patient was unconscious for is used to define how serious the brain injury is.

Minor brain injury

  • less than 15 minutes unconscious
  • less than 1 hour PTA

Moderate brain injury

  • between 15 minutes and 6 hours unconscious
  • between 1 hour and 24 hours PTA

Severe brain injury

  • between 6 hours and 48 hours unconscious
  • between 1 day and 7 days PTA

Very severe brain injury

  • over 48 hours unconscious
  • over 7 days PTA

The severity of the brain injury will determine the effects of it. With relatively minor head injuries the only symptom may be epilepsy. For more serious brain injury this may cause a coma or epilepsy.

See our section on the consequences of a brain injury for more information.

To contact a member of the Head Injury team please call us on: 0800 073 0988 or Email: info@headinjuryuk.com