Differential Diagnosis: Confirming Your Diagnosis: "How does your doctor figure out your diagnosis? His thought process should work like that of a detective. Using clues drawn from your descriptions of symptoms, your medical tests, his knowledge of medicine, and additional input, your doctor will make a list of all the possible diagnoses that could explain what is medically wrong with you. Then, one by one, using those same clues, he will begin to narrow down the list by finding clues that don't fit. That process of elimination is called 'differential diagnosis.' Ultimately he will be left with one diagnosis, and that's the one he gives you. What Happens Next? Most patients think the next step is to ask about options for treatment. After all, they want to know how to fix or cure whatever their health problem is. But you, the empowered patient, know better. Or at least you will, once you've learned what to do next. Ask your doctor, 'What else can it be?' These five words can make a major difference in your care."