Common causes of ABI

A brain injury can happen to anyone, anywhere, at any time.

What causes an acquired brain injury?

There are many possible causes of brain injury, including:

  • Trauma – from a road crash, fall, assault, sporting accident, violent shaking, gun shot, or explosion;
  • Medical event – from a stroke or haemorrhage, brain tumour, aneurysm, or infection - including: meningitis, Encephalitis;
  • Degenerative neurological condition - such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, Multiple Sclerosis, or Motor Neuron Disease;
  • Toxins/Poisoning - from alcohol and other drugs, lead, or carbon monoxide;
  • Lack of oxygen to the brain (hypoxia/anoxia - period of reduced oxygen supply) – from near drowning, suffocation, attempted suicide, strangulation, choking, cardiac arrest, or stroke.

How traumatic brain injury can happen

A traumatic brain injury (TBI) is the most common type of brain injury.


This movement of the brain inside the skull is called the ‘contrecoup motion’ and can cause physical injuries to the brain like swelling, bleeding, bruising, twisting – and even tearing of the tissue. 

The contrecoup motion can cause localised damage to the brain but this injury also causes a shockwave to pass through the brain that can cause tearing of neurons as well as swelling and bleeding. This results in damage to the brain and disruption to the brain function that is often permanent and irreversible.

Severity: Mild brain injury doesn't necessarily mean minor effects

Even mild brain injury, commonly referred to as concussion, can cause long-term cognitive problems that affect a person's ability to perform daily activities and return to work.

Learn more about the effects of brain injury.