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Concussion Overview

The term concussion describes an injury to the brain resulting from an impact to the head. By definition, a concussion is not a life-threatening injury, but it can cause both short-term and long-term problems. A concussion results from a closed-head type of injury and does not include injuries in which there is bleeding under the skull or into the brain. Another type of brain injury must be present if bleeding is visible on a CT scan (CAT scan) of the brain.

  • A mild concussion may involve no loss of consciousness (feeling "dazed") or a very brief loss of consciousness (being "knocked out").
  • A severe concussion may involve prolonged loss of consciousness with a delayed return to normal.

Concussion Causes

A concussion can be caused by any significant blunt force trauma to the head such as:

  • a fall,
  • a car accident,
  • sports injury, or
  • being struck on the head with an object.
Medically Reviewed by a Doctor on 11/11/2014

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Concussion - Helpful Diagnosis

Concussion Symptoms and Testing

How Do Emergency Doctors Determine Concussion Risk?

The Canadian Head CT Rules came out the winner when they were compared with the New Orleans rules (even medical decision-making rules can compete against each other). There are five "high risk" and two "medium risk" signs that can predict whether bleeding exists in the brain that will require an operation:

  • High risk: The person is not neurologically normal after 2 hours, has a depressed skull fracture, has a fracture of the base of the skull, has vomited more than twice, or is older than 65.
  • Medium risk: The person has had more than 30 minutes of amnesia, or the injury occurred as a result of a dangerous mechanism like being thrown from a car.

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