A brain injury can be defined as a result of an action which impedes on the brain, causing it to be damaged, and therefore prohibited from performing its correct functions. Brain injuries can occur in a manner of ways. Some may occur suddenly, through blunt force trauma or a stroke, whereas some are less immediately onset, such as prolonged illicit substance abuse or degenerative diseases.

There are many causes of brain injury, but they are all generally separated into two types:

Causes of Traumatic Brain Injury (TBI)

Traumatic brain injuries are categorized as varying levels of damage to the brain through any external force. 

Some possible sources of injury can include:

  • Physical violence
  • Sports injuries
  • Blows to the head
  • Falls/trips/accidents
  • Car/road traffic accidents
  • Gun accidents

When a TBI event occurs, the brain is often quickly pushed against the skull with force. This can cause a range of damage, including bleeding, bruising, or swelling to the brain.  TBIs can result from a jolt or bump to the head or even a penetrative injury, and often come in different severities.

For example, a 'mild' injury with a short-term consequence may be a concussion or short term memory loss, whereas a more 'severe' injury may come with a more long-term or lifelong consequence, such as permanent brain damage.

The level of damage from a TBI is dependent upon various factors, including on:

  • the force of the impact,
  • whether bleeding around the brain has occurred, or
  • if the damage done is irreparable.

Causes of Acquired Brain Injury (ABI)

ABIs are a broader description of injuries that encompasses TBIs. This kind of injury can be caused by an internal problem (for example, a medical condition as opposed to a sporting accident). They are not congenital and cannot be inherited. In short, an ABI is any brain damage occurring after birth.

Some example of causes of ABIs include:

  • Strokes and heart attacks
  • Poison or exposure to toxic substances
  • Tumours and aneurysms
  • Strangulation
  • Choking or drowning
  • Drug abuse
  • Encephalitis (often referred to as water on the brain)
  • Meningitis and other infections

Both ABIs and TBIs can cause the brain to be starved of oxygen for a prolonged period of time; called anoxic brain injury. It is this action which can leave the brain injured or damaged. TBIs are found under the larger umbrella of ABI because both occur post-birth and are in fact acquired, albeit TBIs are caused by external factors.

Although the above-listed incidents are said to cause ABIs, there are often more specific things happening to the brain during an event which is ultimately the cause of said injuries. The brain controls everything we do. It is made up of different lobes and areas which are all responsible for different actions. When one of these incidents takes place, such as the contraction of meningitis or a puncture wound to the head, the incident can cause an array of traumas, including swelling, blood clots, lack of blood in the brain, or a burst blood vessel.