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(Closed Head Injury; Head Trauma)

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A concussion is a mild brain injury in which trauma to the head results in a temporary disruption of normal brain function. The injury may involve subtle pulling, tugging, or shearing of brain cells without causing any obvious structural damage. After a concussion, the brain does not work right for a while. Loss of consciousness may or may not occur, but confusion or problems with awareness or memory are usually present. Three grades of concussions were developed by the Brain Injury Association and Academy of Neurology:

  • Grade one —temporary confusion, but conscious
    • Symptoms usually clear up in less than 15 minutes.
  • Grade two —confusion and amnesia, but conscious
    • Symptoms last for more than 15 minutes.
  • Grade three —loss of consciousness for a few seconds or longer


Anything that makes the brain bounce around and against the side of the skull can cause a concussion. For example:

  • A blow or jolt to the head
  • Severe jarring or shaking
  • Abruptly coming to a stop

How a Concussion Occurs

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Concussion often results from accidents that involve:

  • Motor vehicles
  • Bicycles
  • Skates, skateboards, and scooters
  • Sports and recreation
  • Falling down
  • Firearms
  • Physical violence
  • Assault and battery
  • Domestic violence
  • Child abuse

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:

  • A previous concussion or head injury
  • Sex: male
  • Certain age groups:
    • Children aged five years or younger
    • Teens and young adults aged 15-24
    • Persons over 75 years old
  • Contact sports, such as football or boxing
  • Work that involves farming, logging, or construction
  • Traveling by vehicle at a high rate of speed
  • Use of alcohol
  • Lack of sleep
  • Medications that cause drowsiness


A concussion causes symptoms that may last for days, weeks, or even longer.

Symptoms include:

  • Confusion
  • Loss of memory about the accident
  • Low-grade headaches or neck pain
  • Nausea
  • Having trouble:
    • Remembering things
    • Paying attention or concentrating
    • Organizing daily tasks
    • Making decisions and solving problems
  • Slowness in thinking, acting, speaking, or reading
  • Feeling fatigued or tired
  • Change in sleeping pattern:
    • Sleeping much longer than usual
    • Trouble sleeping
  • Loss of balance
  • Feeling light-headed or dizzy
  • Increased sensitivity to:
    • Sounds
    • Lights
    • Distractions
  • Blurred vision or eyes that tire easily
  • Loss of sense of taste or smell
  • Ringing in the ears
  • Mood changes:
    • Feeling sad, anxious, or listless
    • Becoming easily irritated or angry for little or no reason
    • Lacking motivation

Symptoms that may appear in a child with a concussion include:

  • Listlessness or tiring easily
  • Irritability or crankiness
  • Changes in:
    • Eating or sleeping patterns
    • Play
    • Behavior
    • School performance
  • Lack of interest in favorite toys or activities
  • Loss of new skills, such as toilet training
  • Loss of balance, unsteady walking


The doctor will ask you and others who were present at the time of injury about your symptoms and how the injury occurred. The physical exam usually includes checking for strength, sensation, balance, reflexes, and memory.

Tests may include:

CT scan —a type of x-ray that uses a computer to make pictures of structures inside the head

Magnetic resonance imaging (MRI) scan —a test that uses magnetic waves to make pictures of structures inside the head


The goal of treatment is to allow the brain injury to heal.

Treatment may include:

  • Rest—providing adequate time for recovery
    • This means not rushing back into daily activities such work or school.
  • Observation by a responsible adult—someone to awaken you every few hours as advised by your doctor
    • The doctor will explain how to watch for complications such as bleeding in the brain.
  • Limiting exposure to drugs—not taking medicines without your doctor's permission
    • This is especially true for aspirin, blood thinners, and drugs that cause drowsiness. Avoid use of alcohol and illicit drugs.
  • Preventing re-injury—avoiding activities that might jolt or jar your head
    • Never return to a sports activity until your doctor has given you clearance. This is generally when signs and symptoms are gone (during rest and activity) and neurologic exam is normal. Ask when it's safe to drive a car, ride a bike, work or play at heights, or use heavy equipment since re-injury can lead to more severe or long-term symptoms. It is recommended that athletes return to play using a gradual, stepwise approach.
  • Preventing "second impact syndrome"—avoiding a second head injury in children and adolescents who have had a concussion
    • Even a mild second injury in children and adolescents can rapidly increase swelling, causing unconsciousness and even death. Opinions vary regarding when it is safe to return to contact sports or other activities that may lead to another concussion. Parents should seek medical attention for any child with a concussion and address the issue of returning to activities.
  • Neuropsychological testing—testing performed by a doctor to determine the stage of recovery and readiness for activities, such as ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing)


The following safety measures may help you avoid getting a concussion:

  • Don't drink and drive.
  • Avoid use of sedating drugs, especially when driving or using heavy equipment.
  • Obey speed limits and other driving laws.
  • Always use child safety seats, seatbelts, and shoulder harnesses in vehicles. Also learn how to safely use air bags.
  • Wear a helmet when:
    • Riding a bike or motorcycle
    • Playing a contact sport such as football, soccer, or hockey
    • Using skates, scooters, and skateboards
    • Catching, batting, or running bases in baseball or softball
    • Riding a horse
    • Skiing or snowboarding
  • Make sure your child's playing surface is soft and free of rocks, holes, and debris.
  • Reduce falling hazards at home for children and adults.
  • Wear mouth guards, face guards, pads, and other safety gear during sports.


American Academy of Physical Medicine and Rehabilitation

American Association of Neurological Surgeons

Brain Injury Association of America

Brain Injury Society

National Resource Center for Traumatic Brain Injury


Brain Injury Association of Alberta (BIAA)

Ontario Brain Injury Association


American Association of Neurological Surgeons website. Available at: .

Can you recognize a concussion? American Academy of Physical Medicine and Rehabilitation website. Available at: .

Centers for Disease Control and Prevention website. Available at: .

Closed head injury. EBSCO Dynamed website. Available at:

Harmon KG. Assessment and management of concussion in sports. Am Fam Physician . 1999 Sep 1.

Kirkwood M., Yeats, K., Wilson, P. Pediatric sport-related concussion: a review of the clinical management of an oft-neglected population. Pediatrics . 2006. 117(4);1359-1371. Available at: .

National Center for Injury Prevention and Control website. Available at: .

Sports-related concussion information for athletes. Wesleyan University Athletic Injury Care website. Available at: .

Last reviewed May 2008 by John C. Keel, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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