In rare diseases like haemophilia, access to information and experience as well as social and psychological support from social and scientific environments, especially from one’s peers and family, is important as the treatment itself. The development of social networks with the advance of communication technologies may provide health benefits for establishing and strengthening a support system. Focusing on communication and interaction in haemophilia-centred Facebook communities in Turkey, this study aims to analyse the roles and functions of such online communities in sharing and mitigating the health problems of haemophilic individuals and offering them social and psychological support. Accordingly, out of the 25 Facebook communities with Turkish content, all 10 active and open-access communities were included in the research sample and analysed through discourse analysis. The research discloses that there are discursive and functional differences in online communities established by individuals and institutions. Whereas the pages managed by organizations include more informative content with little interaction, the individual pages play a more affective role in the daily lives of haemophilic individuals, resulting in a strong network of solidarity. Therefore, the discourse on online communities were classified into two main categories, namely information exchange and emotional support. The current research on Turkey reveals the role of online communities in haemophilic individuals’ access to information on haemophilia and its treatment as well as social and psychological support. Moreover, the current research also provides room for discussion on how these online communities can better contribute to solidarity between haemophilic individuals, families, and health professionals.