Wednesday, October 22, 2014

The natural history of symptoms in primary care

- Kenny Lin, MD, MPH

Not long ago, I was sitting in my office catching up on some electronic charting when I began to feel chilly, achy, and weak. I went home, skipped dinner, and went straight to bed. Although I felt mostly better the next morning, my appetite didn't fully return until later in the day. My self-diagnosis: probable viral infection. But the truth was that I had no idea if my symptoms were related to any kind of disease.

Medical education trains physicians to approach patients' symptoms foremost as manifestations of an underlying cause. Only "treating the symptoms," in contrast, can often feel like a sort of failure. But as Dr. Kurt Kroenke reported in a narrative review published in the Annals of Internal Medicine, at least one-third of common physical symptoms evaluated in primary care (including pain, fatigue, dizziness, sleep disturbances, and gastrointestinal symptoms) are "medically unexplained," meaning that they are never connected to a disease-based diagnosis after an appropriate history, physical examination, and testing.

Dr. Kroenke further asserted that viewing symptoms as purely disease-oriented influences the language physicians use to describe them:

The lack of a definitive explanation for many symptoms is further underscored by the use of adjectival modifiers indicating what a symptom is not ("noncardiac" chest pain or "nonulcer" dyspepsia) or implying causal explanations that are weakly defensible ("tension" headache, "mechanical" low back pain, or "irritable" bowel syndrome).

Not only do some symptoms have no obvious causes, but others have multiple possible causes which may be unproductive to approach separately. For example, why does a patient with congestive heart failure, anemia and depression feel tired all the time? Also, symptoms usually occur in a group, rather than in isolation; for example, a classic symptom cluster in cancer patients is SPADE (sleep  / pain / anxiety / depression / energy).

Studies show that about a quarter of symptoms that present to primary care eventually become chronic. Fortunately, very few of these patients harbor a serious missed diagnosis such as an occult infection or cancer. As family physicians know, even if we are uncertain about if or when a particular symptom might improve, communication still has great therapeutic value. "Is this normal, doctor?" is the question I hear most frequently from my patients who have persistent symptoms without diagnoses. I usually respond that there is a wide range of "normal," and what's more important to me is working with him or her to make these particular symptoms more manageable.