The news that British actress Natasha Richardson may be in critical condition after falling on a beginner’s ski slope highlights the importance of taking proper safety measures to prevent head injury. The incident also points out the insidious nature of some types of head trauma.

Reports say that the 45-year-old Richardson was participating in a beginner’s skiing lesson at the Mont Tremblant ski resort in Montreal when she fell. The accident occurred in a flat portion of the ski run and did not involve a collision with another person or object. She was not wearing a helmet at the time of the fall.

According to reports, there were no obvious signs of injury, and Richardson was walking and talking normally not long after the accident. About an hour after the fall, Richardson began experiencing headaches and was taken by ambulance to a nearby hospital. Unconfirmed reports say the hospital has her listed in critical condition while other reports say she has been transported to a hospital in the U.S.

You may be asking, how could such a seemingly benign incident end up becoming a serious tragedy? The answer is related to the insidious nature of certain types of head trauma. Whenever the head is whipped back and forth abruptly or impacts a solid surface such as the ground, the brain collides with the inner surface of the skull. If the impact is hard enough, the person will likely lose consciousness, but if not there may not be any immediate symptoms.

This does NOT mean there is no cause for concern. Such an impact can cause the brain to swell slowly, a process that can occur over minutes or even hours. Because the brain is housed in the thick, unforgiving casement of the skull, swelling is very dangerous. It pushes the brain up against the sides of the skull, compressing it and causing symptoms ranging from headaches to loss of consciousness. If the pressure is not relieved quickly, the person may die.

This is why anyone who suffers a blow to the head should be monitored carefully for the ensuing day to make sure that no problems occur as a result of brain swelling. It is also why it is very important to wear a helmet when participating in any activity with a high risk of falls or collisions. This includes such common activities as skiing, biking, and skating. Remember that even a low speed crash can cause head trauma, so don’t skip the safety gear just because you are not going "all out."

For more information on head trauma or to share your own experience, join the Healia Support Group for Head and Brain Injuries.