One and a half years of medical school has at least taught me one thing: medicine is all about getting the right diagnosis. Sure, there are important things like treatment, but honestly, evidence based treatment guidelines and experiential wisdom can all be looked up. And as people realize that the way we teach is just as important as what we teach, most clinically savvy professors have done away with the old-school method of disease definitions. These days they give us the symptoms, we generate a differential diagnosis (the list of likely issues based on the case history), and then we learn the diseases.
And so basically, as medical students we’re taught pattern recognition and probabilities. Have a person in the hospital that has sudden kidney failure a few days after an aggressive bacterial infection? That’s the classic pattern for aminoglycoside toxicity.
Or maybe you’re told your patient who has a terrible cough that won’t go away. She’s worried because she watched a movie with someone who had lung cancer that coughed in similar way. Without any other information, sure, some sort of lung or throat cancer is on your differential. Find out she’s never smoked and hasn’t had unexplained weight loss? Suddenly the chances of her having cancer are much lower. And then it turns out she has high blood pressure and is on an ACE Inhibitor. The odds are completely different now. Cancer is way down and side effect of her medication is really high on the list.