The online Health information category got a healthy prognosis today. According to a study conducted by comScore, health information Web sites grew 21 percent over the last year – more than four times the growth rate of the total U.S. Internet population. WebMD Health led the category with 17.3 million visitors in July (up 3 percent versus year ago), followed by Everyday Health with 14.7 million visitors (up 63 percent), Revolution Health Network with 11.3 million visitors (up 182 percent), and AOL Health with 11.1 million (up 88 percent). The visitor spike in the latter two were due, in part, to a combination of partnerships and acquisitions.

*Due to the transition of AOL Body to AOL Health in June 2008, the July 2007 AOL figures reported in the above chart are for AOL Body while the July 2008 figures are for AOL Health.

“Improved site functionality, increased content personalization, and overall consumer acceptance of the Internet as a source for health information have helped to breathe new life into the health information category,” said John Mangano, senior director, comScore Pharmaceutical Marketing Solutions. “Most sites have become vibrant online communities rooted in sharing experiences and advice, rather than simply being one-way information resources for the consumer. As Google and Microsoft ramp up efforts with their respective health sites, Google Health and Microsoft HealthVault, it will be interesting to see how the category continues to evolve.”