It’s a brain injury.  It’s serious.

Only recently have we begun to understand what occurs to the brain during a concussion. In the past, people used the analogy that a concussion was a “bruise to the brain.” It is actually a very complex physiologic event. Common sports injuries such as torn ligaments and broken bones are structural injuries that can be seen on x-rays or felt during an examination. A concussion, however, affects how the brain works. It’s a problem of function, not structure. That is why brain CT scans and MRI results are normal with most concussions. A concussion is not an injury that can be seen.


Even what appears to be a mild jolt or blow to the head or body may cause the brain to shift or rotate suddenly within the skull. This sudden movement of the brain causes stretching and tearing of brain cells, damaging the cells and creating chemical changes in the brain. These chemical changes result in physical, emotional, and cognitive symptoms (see the symptom checklist for common signs/symptoms of concussion). Once these changes occur, the brain is vulnerable to further injury and sensitive to any increased stress until it fully recovers. Studies suggest that it usually takes brain cells about three weeks to regain normal function, but it may take even longer.

Whether it happens while playing sports, at work, or just slipping on an icy sidewalk. Head injuries can range from “mild” to “severe”, with a majority of cases being concussions or mild TBI.

A concussion is a type of traumatic brain injury, or TBI, caused by a bump, blow, or jolt to the head that can change the way your brain normally works. Concussions can also occur from a fall or a blow to the body that causes the head and brain to move quickly back and forth.

Health care professionals may describe a concussion as a “mild” brain injury because concussions are usually not life-threatening. Even so, their effects can be serious.

You can’t see a concussion and some people may not experience and/or report symptoms until hours or days after the injury.The good news is that most cases are treatable and there are several ways to help prevent injury.

Click here for video explanation of a concussion.

Second-Impact Syndrome (SIS)

Second Impact Syndrom occurs when the brain swells rapidly, and catastrophically, after a person suffers a second concussion before symptoms from an earlier one have subsided. This second blow may occur minutes, days or weeks after an initial concussion, and even the mildest concussion can lead to SIS. The condition is often fatal, and almost everyone who is not killed is severely disabled. The cause of SIS is uncertain, but it is thought that the brain’s arterioles lose their ability to regulate their diameter, and therefore lose control over cerebral blood flow, causing massive cerebral edema.

Most cases of SIS have occurred in young people, who are thought to be particularly vulnerable. In order to prevent SIS, guidelines have been established to prohibit athletes from returning to a game prematurely. For example, professionals recommend that athletes not return to play before symptoms of an initial head injury have resolved.