Cranial Diabetes Insipidus is a potentially fatal disorder if not diagnosed and treated appropriately. The diagnosis can either be made in the outpatient setting, whereby the main differential diagnosis is Primary Polydipsia (PP), or during a hospital admission, where patients can be prfoondly unwell, dehydrated and hypernatraemic. In the ouptatient setting, it can sometimes be difficult to distinguish between DI and PP, but usually severe Cranial DI is clinically and biochemically obvious, characterised by extreme thirst and the pasing of high volumes of dilute urine. Cranial DI is usually associated with pituitary disease, although there are other causes which will be covered in the lecture. In the acute situation, there have been high profile cases in the media of potentially preventable deaths. As part of this talk, I will present the findings of a survey done on behalf of the Clinical Committee for the SFE, which higlights common areas of risk around the UK. The hope is that in this session, there will be an interactive discussion with the audience about how we can best educate health care professionals and the public to improve the recognition and understanding of this important condition.