Background: Hypoglycaemia is the most common complication of treatment with diabetic medication and represents the greatest barrier in achieving and maintaining good glycaemic control. Additionally, severe hypoglycaemic events (SHE) are feared not only by patients, but also by their family members. Education targeting improved prediction and avoidance of hypoglycae-mia has been recommended. However, little is known regarding the specific needs of patients and their family members who have experienced SHE and how they could manage subsequent events. Study aim: The purpose of this study is to investigate the presentation of people with SHE to the emergency services, including pre-hospital care with emergency medical services (EMS) and to emergency departments (ED), and how the presentation impacts on family members. Design: Following a systematic literature review, the investigation will be car-ried out in two stages: Phase 1 involves a descriptive, retrospective investigation of hypoglycaemia presentations in a single Swiss ED and its EMS. Phase 2 will be guided by the constructivist approach to Grounded Theory. The first part of Phase 2 explores patients' and their family members' experience of managing SHE. The second part of Phase 2 will explore healthcare profes-sionals' perception of care given in the ED or EMS and their perceptions of patient's and family members' care needs, and the final part of Phase 2 vali-dates the main findings with the involved healthcare professionals, patients and their family members. Discussion: According to the U.K. Medical Research Council framework, the development phase of a new intervention is important for its future success. The proposed study will give a rich insight into how different people deal with SHE. This will enable the development of brief interventions for use by EMS and ED to better support self-management of SHE and potentially prevent subsequent emergency presentations.