Social media is a new form of communication that leverages the Internet to create online or virtual communities. Within these established communities, users develop networks with friends, family, colleagues, businesses, and institutions. Within networks, users can share information, content, news, photos, and videos. These networks can be highly interactive, with users commenting, liking, and sharing posts within their own networks, resulting in the rapid dissemination of information. A central set of characteristics of social media is that the content is highly accessible and can be shared quickly. The net result of these factors is the viral potential of social media, defined as the likelihood that users will rapidly reshare content that they see in their own feeds. 1 Social media has been rapidly growing in popularity and usage. Data from the 2014 Pew Internet Project2 show that 74% of adults who are online use social networking sites, including 49% of adults aged≥ 65 years. The majority of adults (71%) use Facebook, 23% use Twitter, and 26% use Instagram. Two-thirds of US adults using social media receive news items through Facebook or Twitter, 3 and, overall, 10% of US adults receive news reports from Twitter and 40% receive news reports from Facebook. Finally, roughly half of US adults see reports regarding health and medicine content on Twitter and Facebook.

When social media users look for information about health and health care online, they can find posts from newspapers, magazines, and even medical journals. Many medical journals are now using social media campaigns to help disseminate medical information beyond the pages of their journals to a potentially broader audience. 1 In fact, the majority of top medical and cardiovascular journals all have social media campaigns.