Asked how a doctor makes a diagnosis many would answer: “He does a test.”
This is actually uncommon. Experts agree that ninety percent of our diagnoses come from what you tell us.
Having spoken to the hotel guest over the phone, I’m certain of what’s going on when I drive off ninety percent of the time. Ten percent of the time, I’m not certain. Sometimes more talk or the exam gives me better information. Sometimes, almost always if the illness turns out to be worse than I thought, I send the guest off for a test, usually an X-ray.
I carry dipsticks that detect many substances in the urine. Once or twice in thirty years, I’ve discovered a new case of diabetes. I see guests with symptoms of a urine infection perhaps once a week. I always test their urine.
I then look thoughtfully at the test strip before announcing that the guest has a urine infection. In fact, 10-20 percent of the time the results are normal. No matter. If the guest describes symptoms of a urine infection, I make the diagnosis. Doctors often ignore tests, usually for a good reason.