Increasingly these days, when people get sick, they're announcing it to the world using Twitter. It might seem self-indulgent, but it's also a practice that may revolutionize public health research.

In an unprecedented study, Johns Hopkins computer scientists Mark Dredze and Michael J. Paul have analyzed 1.6 million health-related tweets to uncover health trends that are consistent with official government data, plus new findings about self-medication, localized disease outbreaks, and more. They collected 2 billion public tweets posted between May 2009 and October 2010 and used a new proprietary algorithm called ATAM+ to sift through the ones related to health by using keywords linked to various ailments, symptoms, and treatments.