Patients presenting to an Emergency Department with an altered mental state, whether from a psychiatric, medical or surgical condition or a combination of psychiatric and medical or surgical conditions, require more than the usual amount of diagnostic acumen. General medical conditions often appear in the guise of dysfunctional emotions and/or behaviors. Acute and chronic psychosis may mask underlying acute and chronic medical and surgical conditions. As the case of Esmin Green of Brooklyn, New York, illustrates, the failure to identify underlying medical and surgical conditions in delirious, demented, or psychotic patients can prove fatal to the patient and economically costly to the medical center and its employees.