What can we learn from actress Natasha Richardson's awful skiing accident this week? Dr. Steven Flanagan, director of Rusk Institute of Rehabilitation Medicine at NYU Langone Medical Center where I work, rightly characterized Richardson's sudden loss of consciousness after seeming fine at first as possibly "talk and die syndrome." He was quoted right here on FoxNews.com as describing the likely buildup of blood in the head that may have overwhelmed her consciousness and caused her to blackout after first seeming to be okay.

What else can we learn? That a person can be alive and thriving one minute and have her life snuffed out the next? Who among us doesn't know that skiing is a dangerous sport? It has been several years since a blow to my knee convinced me not to take any more chances with my livelihood and health. Unfortunately, not everyone sees it that way.

Not knowing the details, I can't say whether she was taking chances, whether this terrible accident could have been avoided. I can't say whether she had a hidden aneurysm in her brain that predisposed her to a bleed, or even whether prompt medical intervention, drainage and anti-inflammatory medications and life support can still bring her back. We are all hoping to find out that she is back awake and speaking with visitors tomorrow.

As is usual with celebrities, the media reports so far have been shrouded in mystery and contradiction, ranging from minor injury to looming death. As these are sorted out over the next few days, it is worth reminding readers just how often we learn incorrect facts about medicine from the sudden illnesses of those we admire.

Whatever actually happened to Natasha Richardson, and whatever happens from here, there are a few important conclusions we can already draw. 1. Skiing is a dangerous sport which can injure more than your legs. 2. The brain is a closed compartment with no outlet for blood or swelling until the swelling subsides and the blood is reabsorbed. 3. If the brain itself is not damaged, but only swollen or compressed by blood, then there is still hope for her survival.

The latest reports say that she has been flown from Quebec to New York City, and I can attest to the fact that there are medical centers here with the ability to bring people back from a deep coma.

Dr. Marc Siegel is an internist and associate professor of medicine at the NYU School of Medicine. He is a FOX News medical contributor and writes a health column for LA Times, where he examines TV and movies for medical accuracy. Dr. Siegel is the author of "False Alarm: The Truth About the Epidemic of Fear"and "Bird Flu: Everything You Need to Know About the Next Pandemic." Read more at www.doctorsiegel.com