As a process of gathering patient biographical data from the perspective of a hypothesis, anamneses are essential in establishing a medicai diagnosis. Anamneses are basically interpretive procedures that entail a reflective relation between a doctor's suppositions and the behavior and motivations that can be associated to the diagnosis. The article argues that underpinning such diagnostic hypotheses lies an interpretive structure, in turn grounded on common sense procedures. To illustrate this point, an analysis is made of some 140 records on individuais who were seen at a Belo Horizonte hospital emergency room following suicide attempts. In addition, about 20 consultations with patients were observed, and the professionals providing consultations were interviewed.