Part one of a series.

The first patient I ever saw as a first year resident came in with a litany of complaints, not one of which I remember today except for one—he had headaches. The reason I remember he had headaches isn’t because I spent so much time discussing them but rather the opposite: at the time I knew next to nothing about headaches and somehow managed to end the visit without ever addressing his at all, even though they were the primary reason he’d come to see me.

Then I rotated on a neurology service and actually learned quite a lot about headaches. Then when my patient came back to see me a few months later, I distinctly remember at that point not only being interested in his headaches but actually being excited to discuss them.

I often find myself thinking back to that experience when I’m confronted with a patient who has a complaint I can’t figure out, and I thought it would be useful to describe the various reactions doctors have to patients in general when they can’t figure out what’s wrong, why they have those reactions, and what you can do as a patient to improve your chances in such situations of getting good care.

The scientific method
Believing a wacky idea isn’t wacky in and of itself. Believing a wacky idea without proof, however, most certainly is. Likewise, disbelieving sensible ideas without disproving them when they’re disprovable is wacky as well. Unfortunately, patients are often guilty of the first thought error (“My diarrhea is caused by a brain tumor”) and doctors of the second (“brain tumors don’t cause diarrhea, so you can’t have a brain tumor”), leading in both instances to contentious doctor-patient relationships, missed diagnoses, and unnecessary suffering.

Doctors sometimes aren’t willing to order tests that patients think are necessary because they think the patient’s belief about what’s wrong is wacky; they sometimes suggest a patient’s symptoms are psychosomatic when every test they run is negative but the symptoms persist; and they sometimes offer explanations for symptoms the patient finds improbable but refuse to pursue the cause of the symptoms any further.

Sometimes these judgments are correct and sometimes they’re not—but the experience of being on the receiving end of them is always frustrating for patients. However, given that your doctor has medical training and you don’t, the best you can sensibly hope for are judgments based on sound scientific reasoning rather than unconscious bias. Unfortunately, though, even the minds of the most rational scientists are teeming with unconscious biases. So a more realistic strategy might be to attempt to leverage your doctor’s biases in your favor.

Expert versus novice thinking
In order to do this, you first need to know how doctors are trained to think. Medical students typically employ what’s called “novice” thinking when trying to figure out a diagnosis. They run through the entire list of everything known to cause the patient’s first symptom, then a second list of everything known to cause the patient’s second symptom, and so on. Then they look to see which diagnoses appear on all their lists and that new list becomes their list of “differential diagnoses.” It’s a cumbersome but powerful technique, its name notwithstanding.

A seasoned attending physician, on the other hand, typically employs “expert” thinking, defined as thinking that relies on pattern recognition. I’ve seen carpal tunnel syndrome so many times I could diagnose it in my sleep—but only learned to recognize the pattern of finger tingling in the first, second, and third digits, pain, and weakness occurring most commonly at night by my initial use of “novice” thinking. The main risk of relying on “expert” thinking is early closure—that is, of ceasing to consider what else might be causing a patient’s symptoms because the pattern seems so abundantly clear. Luckily, in most cases, it is clear.

But sometimes it isn’t.

Alex Lickerman is an internal medicine physician at the University of Chicago who blogs at Happiness in this World.  He is the author of The Undefeated Mind: On the Science of Constructing an Indestructible Self.