By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) - Social media is very difficult to define because it is a moving target. Whether it is Facebook, Twitter or some other tool, social media has had an impact at many levels. But what about medicine? What has the role been there?

In truth, it has been somewhat limited. One of the problems has been that medical organizations tend to look at what can go wrong rather than how it can be used to help care.

There are some ways that it will make a big difference.

Perhaps the most important reason is that an entire generation that needs to be reached with health information relies on social media. The big step is how to use it effectively, safely and efficiently.