Abstract: A medical diagnostic system and methods that use the complaints or symptoms presented by the patient, along with the physician's top-of-mind diagnoses, to identify in real-time a list of fail-safes that correspond to potential high-risk diagnoses that the patient may be suffering from. The fail-safes are preferably listed in rank order with the most serious on down, and serve as a checklist to remind the emergency physician of possible missed high-risk diagnoses, thereby averting errant diagnoses.