Online health sites have been booming in the past five years, experts say, driven by the popularity of social networking and patients' desire to become more empowered in the medical field. Officials of the Health 2.0 Conference, which tracks the industry, estimate that the number of such sites climbed to nearly 500 from about 35 four years ago. The sites generally have evolved from the encyclopedic-styled WebMD, becoming more interactive and case-study- oriented, such as Inspire, PatientsLikeMe, and CureTogether. Many of the sites have also recently experienced heavy traffic from users seeking information on the H1N1 virus.
