Abstract : Therapeutic education enables patients to develop their self-care and adaptation skills in the management of chronic illness. The aim of our thesis is to understand their nature from every day real-life situations which type 1 diabetics adults and the parents of type 1 diabetics children discuss on asynchronous Internet forums. We analysed 3756 messages written over a three-year period on two discussion forums (314 diabetic patients are included in the study) and we interviewed voluntary patients and users of these forums. We used professional recommendations published by the HAS and the INPES (2007), to link our results to their frame of reference of skills developed by patients suffering from chronic illnesses, and related to educational objectives the topics covered by discussions on forums. Thus, our results bring to light the ability of patients with diabetes to strengthen, via the internet forums, self-care skills in association with their security. The nature of the adaptation and self-care skills indicated by our results emphasizes the relationship that the patients have with the illness and the treatment. The prospects of this thesis are therefore discussed. In order to enable the patients to share in the therapeutic education procedure, as stipulated by current legislation and professional recommendations, the possibility to continue research with examples of other chronic pathologies seems a relevant path to follow. A better understanding of real-life situations and the nature of the skills revealed by exchanges on Internet forums, whilst respecting ethical rules, would permit the elaboration of therapeutic education programmes adapted to the real needs of patients with chronic illness. In addition, our thesis permits an approach to the nature of informal educational situations in relation to everyday life with a type 1 diabetes : we discuss their significance for the elaboration of structured therapeutic education programmes proposed by carers.