Thomas Lee's business cards are stamped with the link to his Facebook page. The orthopedic surgeon actively tweets, checks in regularly on FourSquare, and maintains a GooglePlus profile. And he does it for his patients. "It's an electronic way of extending the conversation," says Lee, who practices at Orthopedic Foot and Ankle Center in Westerville, Ohio. "It creates a vibrant sense of community and a wonderful back–and–forth dialogue."

Social media makes it easier than ever for patients and physicians to connect outside the exam room. And while most of the attention has centered on hospitals' efforts, which are often driven by marketing and have relatively large budgets, primary care and other private–practice doctors are building an online presence. It's too soon to take for granted that your personal physician will be on Facebook or Twitter, but some doctors say that may be the norm within a few years. More than 1,300 doctors have already registered with TwitterDoctors.net, a database of physicians who tweet. "These are powerful, tremendously influential tools," says internist Kevin Pho of Nashua, N.H., a popular medical blogger who engages with his patients via Facebook and Twitter. "Doctors should be taking advantage of the opportunity."

Those who do should find a receptive audience. About 20 percent of patients already use social media to glean healthcare information, according to an April survey by the National Research Corporation, a healthcare research firm based in Lincoln, Neb. Facebook tops the list of sites that survey respondents use for such purposes, followed by YouTube, Twitter, MySpace, and FourSquare. But since anyone can post, the information that gets passed along isn't always accurate. Patients can do better if they follow links posted by social media–savvy doctors to provide a direct route to credible help.

Pho, for example, shares interesting findings and updated medical guidelines on Facebook and Twitter. Anyone can view his professional Facebook page, while his personal account is limited to family and friends. Recent links he's posted for his audience–at–large range from "how to ask for help when chronic pain or illness strikes" to "the fallacies of screening tests."

Glen Stream, a family physician in Spokane, Wash., and president of the American Academy of Family Physicians, touts Facebook as a forum for providing and responding to information. He launched accounts as soon as he was named AAFP president in September. This month he posted a reminder for patients and fellow physicians about the Great American Smokeout and provided resources to someone who happened onto his page and requested information on smoking cessation. He also updates his Twitter followers when he attends medical meetings and conferences. "It's like most innovations—it starts slow and then picks up momentum," Stream says. "I'm sure we'll be seeing a lot more of it in the future."

Beyond link–sharing, doctors are still wary about engaging with patients. Some doctors answer medical questions via social media, but that triggers privacy concerns. Online anonymity is never guaranteed; a patient who tweets details about a diagnosis or treatment could easily be identified, and so could the doctor who might accidentally reveal them. Personal questions should still be handled through doctor's office visits or phone calls.

Still, some primary care doctors are finding innovative ways to add a personal touch to their social media efforts. La Jolla Cosmetic Surgery Centre in California posts success stories and notes from patients in addition to explanations of procedures and treatment options. The practice's Facebook page interacts with patients through polls, virtual birthday celebrations for its doctors, and one–on–one conversations with patients who post comments and questions. It's also increasingly common for gynecologists to take personal interaction a step further and post photos and videos of newborns.