What Causes Brain Injury?



Before reading any further think about the causes of brain injury you are aware of.  See how you go matching up with the list below. Any surprises? Any questions?

Often there are many more causes than people realise. Think about the ages and stages of life, and what types of brain injury might be common to that stage?

Understanding a bit about the brain can help identify what the possible causes might be.

Understanding the causes can help you understand what kind of damage might result.

Both will help you better work with the person you are supporting.

When it comes to brain injury, a little knowledge can go a long way in helping you  support a person with brain injury.

The main causes of brain injury can vary between countries. I remember discussing brain injury with a person who was working in the Pacific Islands, she reported brain injury from coconuts falling from trees was not uncommon, for me living in an Australian city it was unheard of.

In Cambodia a study was undertaken to evaluate trauma and brain injury after the war finding an increase in numbers of people with traumatic brain injury and subsequent depression as a result of the war. The injuries were often through an indirect injury to the brain, such as being close to a bomb blast.

This means the possible causes of brain injury will vary across the world but could include:

Accidents, Injury and Incidents

Accidents and incidents which result in damage to the brain include:

  • work-related accidents,
  • violence such as assaults and shaking,
  • traffic accidents both for pedestrians and vehicle collisions,
  • sporting accidents or increasingly even playing some sports such as boxing, soccer and football,
  • electrical shock,
  • war-related injury both civilians and combatants, direct and indirect, such as being close to a bomb blast.
  • falls are common in young children and older persons and apparently men of retirement age! The latter apparently taking up more risky pursuits such as motorbike riding or falling off ladders as they take up home maintenance

Bleeding anywhere in the brain can cause damage to that part of the brain. This occurs in cerebro- vascular accident (commonly termed CVA or stroke), brain haemorrhage, bleeding into the layers around the brain e.g. subarachnoid haemorrhage, a ruptured aneurysm. Severe blood loss elsewhere in the body can also cause brain damage.

Brain Tumours

It is often thought that only cancerous tumours cause brain damage however even benign (non-cancerous) tumours can cause damage when they take up space the brain needs.


Infection and inflammation of the linings around the brain, or within the brain tissue itself.

  • Meningitis and Encephalitis (both infectious and post infectious autoimmune encephalitis)
  • Late stage Syphilis
  • Complications of infections such as Tetanus, Diptheria, Measles, Malaria
Neurological disorders

The most common neurological disorder causing brain injury at the current time is dementia. Other disorders which can result in brain damage include Multiple sclerosis, HIV/Aids, Motor neurone disease, Parkinsons disease, and Huntington’s disease.

Lack of oxygen

Given the greedy need for energy and blood supply any reduction in the supply of oxygen can cause damage. The situations that might cause this include; near drowning, birth trauma, attempted hanging, severe asthma attack, blood loss from accidents, partial respiratory arrest, anaesthetic error, and heart attack.

Secondary to illness or disease

Brain damage can occur as a result of other disease in the body often as a result of the brain being deprived of oxygen, or being bombarded with toxic by-products.

Examples include diseases of the liver, severe anaemia, some metabolic disorders, severe blood loss, and malnutrition.


Substances, medications and drugs, both prescribed and illegal can cause permanent damage including alcohol, illegal drug use, adverse effects of prescribed medications, exposure to toxic gases, and carbon monoxide poisoning.

Medical intervention

Brain injury can occur sometimes as an expected result or side effect of treatment such as surgery to the brain, but also errors do occur in treatment, surgery, medication, anaesthetic administration which can cause permanent brain damage.


“Why do I need to know this?”

Understanding the causes of brain injury can give you clues to the kind of damage that will likely result. Leading you to a bit of an understanding of what kind of difficulties a person might have.

Some causes result in more direct damage affecting mainly the area where damage occurs such as after stroke, or trauma. A lack of oxygen will more likely result in damage throughout the brain. Neurological diseases, such as Dementia and Motor Neurone disease, will cause deterioration of the functioning of the brain over time.

While there are some similarities in the outcomes of brain injury whatever the cause. Different causes will require different approaches.

If you are supporting a person with a traumatic brain injury (TBI) you will likely use different strategies than with a person with a degenerative condition such as a dementia. The abilities of a person with dementia will continue to change and deteriorate, which will mean changing your approach and strategies. For a person with TBI the damage to brain cells sustained is more likely to stay the same, and the person’s abilities improve with time (and support).

We will talk much more on strategies in the future.


Meanwhile any questions about the causes? Are there any not listed here?


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