Concussion

Medical Author:
Medical Editor:

What is concussion?

Concussion describes a brain injury where, after an injury, there are functional changes that occur in how the brain works but no structural damage can be seen on standard imaging tests like CT scan.

Mild traumatic brain injury, or concussion, can be defined as a short-lived loss of brain function due to head trauma that resolves spontaneously. With concussion, function may be interrupted while there is no structural damage to the brain.

Concussions & Brain Injuries Pictures Slideshow: Symptoms, Tests & Treatment

What causes concussion?

The brain floats in cerebrospinal fluid and is encased in the skull. These protections allow it to withstand many of the minor injuries that occur in day-to-day life. However, if there is sufficient force to cause the brain to bounce against the rigid bones of the skull, then there is potential for injury. It is the acceleration and deceleration of the brain against the inside of the skull that can cause the brain to be irritated and interrupt its function. The acceleration can come from a direct blow to the head or face, or from other body trauma that causes the head to shake. While temporary loss of consciousness due to injury means that a concussion has taken place, most concussions occur without the patient being knocked out. Studies of football players find that most of those affected were not aware that they had sustained a head injury.

Medically Reviewed by a Doctor on 11/6/2015

Patient Comments

Viewers share their comments

Concussion - Cause Question: What was the cause of your concussion?
Concussion - Symptoms Question: What were your concussion symptoms?
Concussion - Treatments Question: What were your treatments of concussion?
Brain with dementia

Sports and Concussions

What Are the Recommendations?

When it comes to making recommendations, doctors' organizations tend to come late to the game, calling press conferences to state the obvious. The American Academy of Neurology states that "any athlete who is suspected to have suffered a concussion should be removed from participation until he or she is evaluated by a physician with training in the evaluation and management of sports concussions." The Academy's position also includes an educational component to increase concussion education for parents, athletes, and coaches; and reminds us that players should not return to competition until they had recovered from their injury.