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.