The word "concussion" is frequently used to describe an event in which the head is struck or strikes something, such as when athletes talk about having their "bell rung." However as a result of increased understanding of brain injury, concussion is now taken more seriously by medical personnel, coaches, and athletic trainers. A concussion represents a mild traumatic brain injury.

For example, the American Academy of Neurology has developed a standardized assessment of concussion, and encourages its use for measuring three grades of concussion (I, II III) suggesting appropriate bench time before returning athleltes to play.

A person sustaining a Grade I concussion might appear confused with no loss of consciousness and have difficulty maintaining a coherent conversation. The symptoms should resolves within 15 minutes.

A Grade II concussion may have very similar symptoms. However, they last beyond the 15 minute time frame.

Any loss of consciousness would be a result in a Grade III concussion and a person should be seen by a physician at once.