The patient, a man in his 40s, came to my office on a recent hot summer afternoon. All I'd been told before he arrived was what my secretary had typed next to his name when she scheduled the urgent appointment: "doesn't feel well." Yet somehow I felt certain, even seeing only his name and this telegraphic notation, that he'd have Lyme disease.
When I walked into the exam room I found the man lying on the table, shivering. He said he'd pulled a tick out of his skin two weeks earlier and since then his joints had been sore, his head had ached, and he'd had chills. None of this surprised me. In fact, as my patient spoke, I had the eerie feeling I knew what he would say before he said it. The only surprise was when I asked if he had a rash; he said no. But then I asked him again, and he said maybe there was a red area where his leg had chafed from lying around so much while he was ill. I peeled back the sheet to reveal what I knew I'd find: the classic, oval-shaped bullseye rash of Lyme.
The feeling of knowing something you don't have an apparent reason to know is called intuition — and doctors and nurses experience it all the time. Given how common intuition is in medicine, it's still quite hard to define.
Several studies have questioned the validity of intuitive healing, an ability claimed by some alternative practitioners. However, I do think that certain intangible factors — patients' emotions and the emotions they elicit in the clinicians caring for them, for example — can assist in diagnosis. I recall being told as a medical student that if a patient made me feel sad they were likely depressed, and if they made me angry they might have borderline personality disorder. I also learned that the most important skill I would develop as an intern was the ability to sense if someone was seriously ill — and that my most important tool for doing so was recognizing my own rush of adrenaline in encountering such a person.
Medical intuition is more than an emotional response, though. In his best-selling book, "Blink," Malcolm Gladwell argues that what we call intuition or gut feeling is often actually a logical, if abbreviated, reasoning process. Gladwell's "rapid cognition" is best exemplified by Sherlock Holmes, the literary creation of physician Arthur Conan Doyle. Holmes could, famously, extrapolate much of a person's life story from a creased sleeve or the sole of a shoe. Real and fictional diagnosticians from Sir William Osler to Dr. Gregory House have used what Holmes called "backwards reasoning" — and astonished their colleagues with what seemed uncanny clinical intuition.
In the case of my patient, my own intuition may have been somewhat Holmesian. I later realized that the appearance of the patient's name and "doesn't feel well" had initiated in me a chain of thoughts of which I was barely conscious at the time: He's always been healthy . . . rarely comes in except for routine visits . . . no mention of a single specific symptom . . . probably a systemic illness . . . most likely an infection . . . it's not flu season . . . but it is Lyme season!
I sent off blood tests for Lyme and other tick-borne infections as well as a complete blood count and metabolic screens. Meanwhile, as is recommended for people who live in areas where Lyme is prevalent and who have a typical rash and symptoms, I started him on a course of antibiotics without waiting for the test results.
The next day, I called the patient expecting him to tell me that he felt very much improved. He did not. He still had a headache and his joints still hurt. Maybe he was a tiny bit better, he said, but not much. I checked his lab results and found that everything was normal except the Lyme test, which had been read as "equivocal." Lyme tests are frequently unreliable, often negative in early cases, or falsely positive. While we waited for the results of a more sensitive Western blot test, I told my patient to stay on the antibiotics.
A few days later the Western blot came back negative. Though this result didn't completely rule out the possibility of Lyme disease, I began to feel less confident in my diagnosis. Could it be that my strong intuition had led me astray? That I'd perceived his rash as typical of Lyme because that's what I expected? I wondered if I'd failed to heed Sherlock Holmes's famous warning: "It is a capital mistake to theorize before you have all the evidence."
When I called the patient again, he reported good news: within two days of starting the antibiotic, he'd felt 100 percent better. I told him to continue the full course of the medication.
Conditions such as Lyme disease, for which we do not yet have a definitive test, highlight how complicated the diagnostic process can be, involving the patient's account of his or her illness, the physician's knowledge of the body's functions and malfunctions, environmental factors, the physical examination, lab and X-ray tests, and, yes, intuition. Computers, which can process enormous amounts of data but which lack intuition, have not, as yet, proved to be infallible diagnosticians.
Philosopher and physician Hillel Braude, who has written extensively on this subject, points out that clinical intuition may be best thought of as a means of bridging the gap between what a doctor knows generally about a condition, and what he observes and feels when interacting with an individual patient.
I'll see my patient again soon and consider retesting him for Lyme. If the test is positive, my intuition will be validated. If it's negative, I'll still believe he had Lyme based on his history, his physical exam, and his response to treatment. But if he hadn't gotten better, then my initial intuition — powerful as it was — wouldn't have been worth a thing.