The Evidence Concussion · Repeated head impacts · CTE What we know, and what we don't

What Does the Evidence Say?

Repeated head impacts have raised important questions about brain health in sport. Here's what research tells us about concussion, CTE, and what athletes should know.

Rugby league State of Origin match: a New South Wales player carrying the ball is wrapped up in a tackle by several Queensland defenders.

01 Two different things

Concussion Isn't CTE

A simple side-view illustration of the human brain.
Injury

Concussion

A concussion is a traumatic brain injury that can temporarily affect how the brain functions. Symptoms vary, and recovery differs between individuals.1

Disease

CTE

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive head-impact exposure. It is characterised by an abnormal accumulation of tau protein in the brain and can currently be definitively diagnosed only by examining brain tissue after death.4

02 The science

What Does the Research Tell Us?

Two researchers in lab coats work together at a laboratory microscope.

What We Know

  • Repeated head impacts are associated with CTE.4
  • CTE has been identified in the brains of some former athletes exposed to repetitive head impacts.6
  • Research continues to investigate how exposure, genetics, and other factors may influence risk.5

What We Don't Know

  • How common CTE is among all athletes.
  • Why some people develop CTE while others with similar exposure do not.
  • The precise relationship between different levels of head-impact exposure and the likelihood of developing the disease.5
A basketball player sits on the court holding a towel to his face while a team staff member kneels beside him to check on him.

03 Putting it into practice

What Does This Mean for Athletes?

Recognise the Signs

Headaches, dizziness, confusion, balance problems, and memory difficulties can occur after a concussion. Symptoms vary, and some may develop later.3

Speak Up

Report suspected concussion symptoms to a coach, medical professional, or trusted adult. Don't hide symptoms to stay in a game.3

Prioritise Recovery

Stop playing when a concussion is suspected and seek appropriate medical assessment. Return to sport should follow professional advice and the relevant sporting guidelines.2

04 Trusted Australian sources

Keep Learning

External websites · open in a new tab

A Concussion in Sport Australia The AIS national concussion hub, including the guidelines for youth and community sport. B AIS: Advice for Athletes From recognising concussion to a staged return to sport. C Healthdirect: Concussion Australian Government information on symptoms, signs and treatment.

References

  1. Healthdirect Australia. Concussion: symptoms, signs and treatment.
  2. Australian Institute of Sport. Concussion and Brain Health in Sport.
  3. Australian Institute of Sport. Concussion: information for athletes.
  4. Babcock KJ, Abdolmohammadi B, McKee AC (2025). Recent advances in chronic traumatic encephalopathy. The American Journal of Pathology. doi.org/10.1016/j.ajpath.2025.07.008
  5. Asken BM, et al. (2025). Chronic traumatic encephalopathy: state-of-the-science update and narrative review. The Clinical Neuropsychologist. doi.org/10.1080/13854046.2025.2454047
  6. Mez J, et al. (2017). Clinicopathological evaluation of chronic traumatic encephalopathy in players of American football. JAMA, 318(4), 360–370. A study of a convenience sample of brain donors. doi.org/10.1001/jama.2017.8334

The Game Is Bigger Than the Scoreboard.

Protecting your brain is part of looking after your future in sport and beyond.

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