In this guide:
An acquired brain injury (ABI) is caused by any damage to the brain that happens after birth. Because the brain controls how we move, think, feel and connect with others, an injury can affect almost every part of a person’s daily life.
According to Brain Injury Australia, brain injury results in a deterioration in cognitive, physical, emotional or independent functioning. The effects of ABI are wide‑ranging, and every person with an ABI experiences different types of symptoms and levels of severity.
What are the common causes of a brain injury?
Brain injuries can be caused in a number of different ways, from a sudden blow to the head to infections, strokes or long‑term health conditions. When an ABI occurs, it may bruise or tear brain tissue, reduce blood or oxygen supply, cause swelling, or leave scarring that interrupts how the brain sends messages through the body.
Traumatic brain injury due to accidents or injuries
This is what comes to mind for most people when thinking about brain injuries. Traumatic brain injury occurs when an external force jolts the head, causing the brain to hit the inside of the skull, or when an object penetrates the skull. Common causes are car accidents, falls or sports injuries.
Concussions are the most common type of TBI, often referred to as mild traumatic brain injury (mTBI). They can happen without any loss of consciousness and should be taken seriously, regardless of how minor they may seem. The HeadCheck app can help identify signs of a concussion.
Tumours and brain cancer
Tumours can damage brain tissue directly and affect the structures around them. There are many different types of brain tumours, and their impact depends on whether they are cancerous, how fast they grow, and their location.
Stroke
A stroke interrupts the brain’s blood supply and can cause lasting damage. An ischaemic stroke occurs when a blood vessel is blocked, while a haemorrhagic stroke happens when a vessel bursts or leaks. Both are medical emergencies where early treatment is critical.
Infections
According to Synapse Australia, Infections such as meningitis (inflammation of the brain’s protective membranes) and encephalitis (inflammation of the brain itself) can cause swelling, bleeding and the death of nerve cells in the brain. Other conditions, like brain abscesses or hydrocephalus, can also lead to ABI.
Interruption of brain's oxygen supply
Known as hypoxia or anoxia, reduced oxygen flow to the brain can cause brain cells to die in as little as a few minutes. This can happen because of a near drowning incident, drug overdose, strangulation, severe asthma attack, or cardiac arrest.
Alcohol or drug abuse
What effects can a brain injury have on an individual?
The effects of an ABI can range from mild to severe. Some symptoms may improve over time, while others can cause lasting changes. Understanding these effects is the first step toward finding the right support, helping people and their loved ones feel more equipped and connected. Find out more about the effects of ABI in these factsheets by Synapse Australia.
Mild effects
Often linked with concussions or less severe brain injuries, these may resolve over days to weeks.
- Cognitive: Difficulty concentrating, short attention span, mild short‑term memory loss (forgetting names, misplacing items), feeling slowed down.
- Physical: Fatigue, headaches, mild dizziness, changes in sleep patterns.
- Psychological: Mood swings, mild anxiety, or irritability.
Moderate effects
Moderate brain injuries may affect daily life more noticeably and often require medical treatment or ongoing support.
- Cognitive: Challenges with planning, problem‑solving and decision‑making, perseveration (repeating behaviours or thoughts), lack of motivation (adynamia).
- Physical: Persistent headaches such as migraines, vision or hearing difficulties, balance problems, seizures requiring medication, sensory changes (including smell).
- Behavioural: Impulsive behaviour, emotional outbursts, reduced awareness of behaviour or limitations.
- Psychological: Ongoing anxiety, stress or panic attacks, depression or persistent sadness.
Severe effects
Severe brain injuries can be life‑changing and often cause long‑term disability.
- Cognitive: Profound memory loss, significant difficulty communicating or understanding language, inability to concentrate or make decisions without assistance.
- Physical: Frequent or uncontrolled seizures, paralysis or severe coordination problems, major sensory loss, sexual function changes.
- Behavioural: Extreme disinhibition, acting in ways that may be unsafe or socially inappropriate.
- Psychological: Emotional instability, severe depression, or a dual diagnosis (ABI combined with another mental health condition such as clinical depression).
In extreme cases, traumatic brain injury can also cause an altered state of consciousness, such as a coma, vegetative state and brain death.
Support for people with ABI and their families
ABI not only affects the person living with it, but also their family, friends, workplace and community. While families and loved ones play a vital role in caring for a person with an ABI, extra support is often needed.
Independent support workers on Mable are here to help people manage the effects of ABI and keep their independence, offering support like:
- Personal care and assistance with daily routines
- Help around the house, like cleaning and gardening
- Allied health services such as physiotherapy and speech pathology
- Transport to and from appointments, work and activities
- Help with managing memory issues, organisation and personal admin
- Social connection, hobbies and community participation.
Carers often also need support too, to take time out for themselves and invest in their own wellbeing. Independent support workers on Mable can provide practical help at home, as well as respite care so that carers can take well-earned breaks.
Find out more about the types of support available on Mable.
Frequently asked questions
What are the most common causes of an acquired brain injury in Australia?
According to Synapse, some of the most common causes of ABI include traumatic brain injuries from falls, car accidents or assaults, strokes, infections like meningitis or encephalitis, brain tumours, and oxygen deprivation from incidents such as near-drowning or cardiac arrest.
Can the effects of an acquired brain injury change over time?
Yes. Some effects may improve with rehabilitation, while others can become more noticeable months or even years after the injury. For example, issues with memory, mood or fatigue might appear later as responsibilities or demands increase. Ongoing support and regular reviews with health professionals help ensure that changes are identified and managed early.
What are the common early symptoms of an acquired brain injury?
The early signs of an ABI can vary depending on the type and severity of the injury, but some common symptoms include:
- Loss of consciousness
- Persistent headaches or dizziness
- Memory problems or confusion
- Difficulty concentrating or staying focused
- Fatigue or disrupted sleep
- Problems with balance, coordination or mobility
- Sensory changes, such as blurred vision, hearing difficulties or sensitivity to light and noise.
Because these symptoms can develop gradually or be mistaken for other issues, it's important to seek medical advice if they appear, especially after a head injury or health event like a stroke.
When should you seek urgent help after a head injury?
It's recommended that you call an ambulance (000) straight away if someone loses consciousness, repeatedly vomits, has a seizure, experiences worsening headaches, increasing confusion, weakness on one side of the body, or difficulty waking up.
If it's not an emergency but you are still unsure, the HeadCheck app can help identify signs of a concussion.
The information provided in this article is general information only and based on current information at the date of publication. In addition to considering the information shared in this article, Mable encourages you to conduct your own research and seek independent advice about managing life with an acquired brain injury.