While social media interactions are currently not fully understood, as individual health behaviors and outcomes are shared online, social media offers an increasingly clear picture of the dynamics of these processes.Social media is becoming an increasingly common platform among clinicians and public health officials to share information with the public, track or predict diseases.Social media can be used for engaging the public and communicating key public health interventions, while providing an important tool for public health surveillance.Social media has advantages over traditional public health surveillance, as well as limitations, such as poor specificity, that warrant additional study.Social media can provide timely, relevant and transparent information of public health importance; such as tracking or predicting the spread or severity of influenza, west nile virus or meningitis as they propagate in the community, and, in identifying disease outbreaks or clusters of chronic illnesses.Further work is needed on social media as a valid data source for detecting or predicting diseases or conditions. Also, whether or not it is an effective tool for communicating key public health messages and engaging both, the general public and policy-makers.