Mild traumatic brain injury (MTBI)

A concussion is a type of mild traumatic brain injury that can occur if you suffer a blow to the head or hit your head after a fall. Concussion results in a short-term loss of normal brain function in response to this head injury.

What is concussion?

A concussion is a type of mild traumatic brain injury that can occur if you  suffer a blow to the head or hit your head after a fall. Concussion results in a short-term loss of normal brain function in response to this head injury.

Concussions are a common type of sports injury. Higher risk sports for concussion include contact activities such as boxing and rugby, but can also occur with virtually any sport with fast movement or balls including cycling, equestrian activities, cricket, hockey and more.

Anyone who knocks their head, (be it playing sport, in a fight or accident) and gets up straight away, still needs to be closely watched. If they show any of the danger signs below, they should receive immediate medical attention. 

Likewise, anyone who is knocked out, meaning they are unconsciousness and can't be woken up, even if only for a minute or so needs urgent medical care to exclude a skull fracture or serious brain injury.

After a concussion, you may have a headache or neck pain. You may also experience nausea, ringing in your ears, dizziness, or tiredness. You may feel dazed or not your normal self for several days or weeks after the injury.

The following video by Dr Mike Evans provides a useful summary of the key points to know. 

(Dr Mike Evans, 2014)

What are the symptoms of concussion?

Symptoms of concussion or mild traumatic brain injury (mTBI) may not appear for hours, days or until you are challenged (physically or mentally) following a head injury.

If you have one or more of the following, check with a doctor as you may have concussion.

  • vision changes
  • sensitive to light or noise
  • feeling sluggish or groggy
  • confusion
  • difficulty concentrating or remembering
  • headache
  • pressure in the head
  • nausea or vomiting
  • sleep changes
  • dizziness
  • mood changes
  • behaviour or personality changes
  • being knocked out (even briefly)
  • answers questions slowly
  • moves clumsily.

Call Healthline on 0800 611 116 if you are unsure what you should do.

Concussion poster and graduated return to play stagesWhat is the treatment for concussion?

Treatment for a concussion depends on the severity of your symptoms. See your health professional if you notice any of your symptoms getting worse, or if you have more serious symptoms such as seizures, feeling drowsy, have trouble walking or sleeping. 

For people with ongoing symptoms, referral through ACC to a Concussion Service may be needed.

  • ACC’s Concussion Service provides early intervention rehabilitation services for ACC clients with a mild to moderate traumatic brain injury.
  • The referral form (ACC883) can be downloaded from the ACC website.
  • Referrers are recommended to send the referral directly to the client’s nearest ACC Short Term Claims Centre.

Return to play

If you have suffered a blow to your head or concussion, it is very important to seek medical advice and NOT to return to sports activities or work (where any further injury is a risk) before you have been cleared as safe to do so.

  • Athletes have ended up with permanent brain damage or died from returning to sport too soon. 
  • See the poster opposite for some minimum stand down times. 
  • Talk with your doctor about what is safest for you.

Learn more

What is a brain injury? Brain Injury New Zealand
Causes and symptoms of concussions Ministry of Health, NZ, 2014
National guidelines for sport concussion ACC, NZ, 2012
Multiple concussions Healthline, US, 2012


Daneshvar DH, Baugh CM, Nowinski CJ, et al. Helmets and Mouth Guards: The Role of Personal Equipment in Preventing Sport-Related Concussions. Clinics in Sports Medicine, 2011; 30 (1): 145-163. [PDF] 
Gavett BE, Stern RA, McKee AC. Chronic Traumatic Encephalopathy: A Potential Late Effect of Sport-Related Concussive and Subconcussive Head Trauma. Clinics in Sports Medicine, 2011; 30(1): 179-188. [PDF]  
Chapter 4: Treatment and Management of Prolonged Symptoms and Post-Concussion Syndrome. Sports-Related Concussions in Youth: Improving the Science, Changing the Culture. Institute of Medicine; National Research Council. National Academies Press (US); 2014 Feb 4. [link to chapter]

Credits: Adapted from National Institute of Neurological Disorders and Stroke, USA & NZ information.