The Hackathon concept is attracting interest as a vehicle for participatory development in both Health and Information systems. Publically available datasets, cloud based data storage, and increasingly sophisticated analytical methods, combined with user friendly development tools for mobile devices are inspiring innovation in the participatory medicine space. This has the potential to disrupt traditional methods and deliver solutions more rapidly, and in a form more likely to meet requirements. In health applications this involves putting the patient and their supports at the centre of design. This work contributes to solving the challenges involved in bringing a diverse cohort of designers, developers, problem owners, healthcare providers, patients, and citizens together to solve user-driven self-care problems using technology. We use a descriptive case study approach focussing on two weekend-long hackathons dubbed "Health Hackathon: Solving Self-care". We gather thick data from multiple sources according to the process defined by Geertz (1994) first, to provide a rich picture of the role of hackathons in participatory medicine and second, to contribute evidence to the practise of running a hackathon. Some key originalities of our work include seeking more candid responses via selfserve interviews. Through this, controversially, we noted a marked emphasis on the creative process over concerns for privacy and ethics around the personal data cloud created by hackathon products. We build on existing theories of participatory medicine and emerging methodologies for conducting hackathons to provide evidence of the efficacy of the hacking approach both in terms of outcome and team dynamics. Through interviews, observation, twitter feeds and a pre-survey, we identify a number of success factors including (1) group size, (2) maturity of the idea, (3) level of involvement of a mentor, and (4) involvement of students. In addition we identify five skills identified by successful health hackathon participants; knowledge, patient focussed skills, analytical skills, software design skills and professional perspective. In common with previous studies we find that there are considerable social benefits that accrue in running a hackathon. Participants meet new people and learn first-hand of the challenges and opportunities provided by the skill sets and work environments of others. This work builds on the existing body of research concerning hackathons and in particular work in the context of participatory medicine