A concussion is an injury to the brain that causes problems with how the brain works. It can affect things like memory, balance, focus, decision making, and coordination.


A concussion is caused by a blow to the head or shaking of the head from things like:

  • Falls
  • Motor vehicle accidents
  • Being struck by something or slamming against something
  • Physical violence

How a Concussion Occurs
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Risk Factors

Concussions are more common in men. Things that raise the risk of this problem are:

  • Alcohol use
  • Playing organized sports
  • A prior concussion


A concussion can cause symptoms that may last for days, weeks, or even longer. They may be start right away or a few hours or days after the injury.

Common physical problems are:

  • Headache
  • Dizziness
  • Ringing in the ears and problems hearing
  • Blurred vision
  • Balance and coordination problems
  • Nausea and vomiting
  • Tiredness
  • Sensitivity to sounds and lights
  • Numbness
  • Seizures
  • Problems sleeping

Other problems may be:

  • Confusion
  • Lack of focus
  • Problems paying attention
  • Loss of memory
  • Slow processing speed
  • Slow reaction time
  • Problems completing tasks
  • Irritability


The doctor will ask about your symptoms and health history. You will also be asked how the injury happened. Others who saw the injury happen may also be asked about it. A physical exam will be done. This is enough to make the diagnosis.


The goal of treatment is to let the brain rest so that it can heal. This may be done with:

  • Time off from sports
  • Limiting mentally-demanding activities, such as schoolwork and using devices with screens
  • Therapy to help with cognitive function

Steps will need to be taken to prevent a second brain injury. It can lead to serious problems.


To lower the risk of concussion:

  • Use seatbelts, shoulder harnesses, and child safety seats when traveling in motor vehicles.
  • Children should use safe, age-appropriate methods when playing sports.
  • Wear a helmet when doing activities such as:
    • Playing a contact sport like football, soccer, or hockey
    • Riding a bike or motorcycle
    • Using skates, scooters, and skateboards
    • Catching, batting, or running bases in baseball or softball
    • Riding a horse
    • Skiing or snowboarding

Centers for Disease Control and Prevention

Family Doctor—American Academy of Family Physicians


Brain Injury Association of Canada

Ontario Brain Injury Association


Concussion and mild traumatic brain injury. EBSCO DynaMed website. Available at: Updated November 1, 2018. Accessed May 13, 2020.

Lumba-Brown A, Yeates KO, et al. Centers for Disease Control and Prevention Guideline on the Diagnosis and Management of Mild Traumatic Brain Injury Among Children. JAMA Pediatr. 2018 Nov 1;172(11):e182853.

Sports-related concussion information for athletes. Wesleyan University Athletic Injury Care website. Available at: Updated January 2007. Accessed May 13, 2020.

Traumatic brain injury and concussion. Centers for Disease Control and Prevention website. Available at: Updated March 4, 2019. Accessed May 13, 2020.

What can I do to help feel better after a mild traumatic brain injury? Centers for Disease Control and Prevention website. Available at: Updated February 12, 2019. Accessed May 13, 2020.

2/21/2017 EBSCO DynaMed Systematic Surveillance Grool AM, Aglipay M, et al. Association between early participation in physical activity following acute concussion and persistent postconcussive symptoms in children and adolescents. JAMA. 2016 Dec 20;316(23)2504-2514.

Last reviewed February 2020 by EBSCO Medical Review Board Warren A. Bodine, DO, CAQSM  Last Updated: 5/13/2020