Social networks are really useful tools for public communication if we are able to manage them to improve the effectiveness of our messages in terms of engagement of citizens. Health is no exception. On the contrary, it is a fertile ground on which to innovate to make patients' lives easier, increasing online services and stimulating the interaction and communicating with patients. On this basis, we present a research about the social communication applied to public services. We analyze it, individuating crucial matters and innovative solutions. Social communication is transparency, involvement and information: three valid key points also for public communication in general, which can move towards new horizons and represents a great opportunity for the public governments. On the basis of statistical analysis and direct experience in Azienda Ospedaliero-universitaria of Cagliari (AOU-Cagliari), we conclude that introducing social media in public organizations, and in health organizations in particular, is not only useful, but it is a real public service. On the one hand, users want to interact and give a feedback; on the other hand, they increasingly require services that are delivered through mobile devices, which avoid waste of time. All these changes can greatly contribute to make the public health and the public administration more citizen-friendly.

In the mediated construction of social reality, public institutions need to in-crease digital communication and build trust through proximity and relationality. During the crisis generated by Covid-19 this has become even more evident. In this paper we will explore some case study of social media communication in ten Italian Health Public Hospitals and Authorities, exploring them in the light of some key perspectives related to four dimensions related to space, time, relational-ity, digital communities and two objectives of public institutions: inclusion and popularity.