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 concussion 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 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 symptoms, past health, and how the injury happened. A physical exam will be done. This is enough to make the diagnosis.



Most people will be able to heal at home. People with severe symptoms may be kept in the hospital for monitoring.

The goal of treatment is to let the brain rest so that it can heal. Some rest is recommended for the first 24 to 48 hours, but full rest is not always needed. It may take longer for all symptoms to pass. Recovery may require:

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

A second brain injury could lead to serious problems. Care will need to be taken to avoid this.


To lower the risk of concussion:

  • Use seat belts, shoulder harnesses, and child safety seats when traveling in motor vehicles.
  • Having children 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

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.