Unexplained Symptoms: When Diagnostic Uncertainty Becomes a Diagnosis

By Susan Carr | Senior Writer, ImproveDx

It is difficult to describe how uncomfortable we physicians feel when we have no idea what is wrong with a patient.1(160)
— Brian Hodges, MD

If I had no diagnosis, then my symptoms meant nothing.1(162)
— Chloe G.K. Atkins, PhD

Uncertainty is a given in diagnosis. Sometimes, when the correct diagnosis comes quickly, uncertainty is brief and mild. Other times, uncertainty settles in as a chronic condition, with unfortunate results for both clinician and patient. Between those two extremes, each case travels through a period of dynamic uncertainty as the patient and clinician work their way through history-taking, physical examination, and testing. Hopefully, uncertainty ebbs as more is known, and the mystery is solved.

Traditionally, the goal of diagnosis is to extinguish uncertainty, with both clinicians and patients invested in finding a clear and accurate answer as quickly as possible. For patients, diagnosis is the key that unlocks the door to treatment and financial support. Having a diagnosis allows them to feel they are on the mend, receiving appropriate treatment or therapy. The clinician can feel satisfied that the case is closed, at least for the time being, and move on to the next.

In addition to providing guidance for effective treatment, diagnosis validates the patient’s experience: symptoms make sense when understood as derived from a disease, condition, or illness. Without diagnosis, symptoms may be seen as subjective and discounted as psychosomatic.

Medically Unexplained Symptoms

Symptoms that clearly affect the patient physically (are not imagined) and are not understood to be associated with an underlying organic disease for an extended period of time have a diagnosis of their own. Referred to as “medically unexplained symptoms” or MUS—also known as MUPS (medically unexplained physical symptoms)—this condition is “largely untreated, common, and costly.”2(689) It is also difficult to define, sometimes used as a catchall for conditions that resist understanding, including conditions that have both physical and psychosocial elements.

MUS is prone to prejudice and cognitive bias. Some patients diagnosed with MUS feel that when an organic disease cannot be found to explain their symptoms, they morph from being the subject of diagnostic interest to being dismissed as difficult and psychologically suspect.1,3,4 And some MUS patients acknowledge that physical and psychological forces coexist and interweave, certainly over time, even if not initially, making it hard for them to perceive and understand their own symptoms.1

Researchers in the United Kingdom found that physicians were more likely to consider symptoms medically unexplained when they had negative perceptions, associated for example with the patient acting anxious, being unmarried, or receiving public assistance. Physicians were more likely to make a provisional diagnosis that “explains” symptoms for patients who were employed, not receiving alternative therapies, and generally viewed as a positive experience for the physician.5

Counting and Classifying MUS

By its nature, medically unexplained symptoms is a condition that is difficult to identify, classify, and manage. It is ill-defined, varied in its presentation, and often unrecognized by patients as a diagnosis in itself. When MUS is recognized and named, the patient may be stigmatized.1,4,6,7 Patients with MUS are prone to being overtested and overtreated.2

In 2007, researchers at Michigan State University estimated that 25% to 75% of outpatients exhibit MUS in manifestations across a clinical spectrum, “i.e., on average, approximately one-half or more of all outpatients have little or no physical disease explanation for their symptoms.”2(685) In 2010, researchers in Germany estimated that MUS represented “two-thirds of all reported symptoms”8(263) in primary care. In 2017, researchers in Denmark distinguished between patients seen without a specific diagnosis and patients diagnosed with MUS, finding the first group represented 1 in 3 consultations, and the second, 1 in 6.9

Those estimates include patients across the spectrum, from those who have mild symptoms that quickly self-resolve to patients who are debilitated for years by physical symptoms and comorbid psychiatric disorders. Most patients whose symptoms resolve easily without specific treatment are never diagnosed with MUS, although they may have ongoing, recurring episodes that are easily managed, amounting to a normal but “worried well” approach to personal health.2 Other patients may develop stress-related symptoms that mimic those of a serious organic disease they have already been diagnosed with, e.g., heart disease.2 These, too, can often be managed as episodic and understandable symptoms, different from chronic, truly unexplained problems.

The population of patients with MUS includes subgroups diagnosed with complex mental and/or physical problems, each with its own special characteristics. Chronic fatigue syndrome, chronic Lyme disease, irritable bowel syndrome, and fibromyalgia are among the diagnoses applied to patients with MUS. Some patients diagnosed with MUS are eventually found to have a rare disease or a rare presentation of a common disease that has confounded diagnosticians in some cases for years. MUS patients may also be found to have “somatoform” disorders, where physical symptoms are caused by a mental disorder, a diagnosis that can be made only after ruling out organic diseases. MUS occurs in children10 as well as in adults.

Uncertainty, a Constant Companion

MUS is both pervasive and largely invisible. When recognized as commonly occurring, it stands as a reminder that uncertainty “typifies the nature and complexity of clinical knowledge”11(244) especially in general practice and could be seen as a constant, not always unwelcome, companion.

Researchers from Scandinavia and New Zealand observe a discord between the “gray-scaled narrative”11(244,)12 of each patient’s experience and “black-and-white diagnosis.”11(244),12 Medical educators in Massachusetts note numerous pitfalls associated with suppressing uncertainty and note that:

Key elements for survival in the medical profession would seem, intuitively, to be a tolerance for uncertainty and a curiosity about the unknown.12(1713)

A strong desire for certainty and diagnostic clarity—felt by clinicians as well as patients—can cause trouble, especially when symptoms remain unexplained over a long period of time. Some patients who continue to need care and persist in pursuit of a diagnosis report developing a reputation among providers for being “difficult,” psychologically unsound, and demanding.1,13,14 Some patients feel their medical records haunt them “like a criminal record,”14(192) prejudicing clinicians against them for the condition that has brought them in for consultation and relief.

In addition to peace of mind, treatment, and insurance coverage, diagnosis provides patients with a recognized label and coherent story—e.g., cancer, heart disease, diabetes—they can use to explain their experience. Louise Stone, a physician, educator, and researcher in Australia, points out that a diagnosis offers meaning that can be structured as a narrative and shared with others. Patients with MUS may become personally invested in a different diagnosis for their unexplained symptoms, replacing uncertainty with a known disease that provides an explanation and story that makes sense to others.

Developing meaning and a coherent story about MUS is challenging but not impossible and may improve outcomes.14 Stone refers to sociologist Arthur Frank’s metaphor of patients feeling shipwrecked by disease as she encourages clinicians to help patients with MUS develop their narratives:

Creating an explanatory framework that respects and incorporates the patient’s models of illness and a future direction for care involves using storytelling ‘as repair work on the wreck.’14(193)

Going forward, knowledge of the wide range of situations currently held under the umbrella of MUS and the current approach to diagnosing and treating them will evolve. Science may provide new understanding to inform diagnosis of specific conditions, such as chronic Lyme disease and fibromyalgia. The interplay between physical and mental health is an active topic of debate among clinicians and is central to the experience of many patients with MUS.1,9 The role of gender in MUS diagnosis must be investigated, as the majority of MUS patients are female, which seems clearly related to earlier beliefs about the role of “hysteria” in illness.3 Researchers note an association of childhood abuse and trauma with adult MUS, which also needs further investigation.14

Diagnosis in Context

The nature of diagnosis itself is also an area of learning. In a clinical commentary to a patient-told story about MUS, Brian David Hodges, MD, points out,

…diagnosis is not a fixed entity—but rather a product of the scientific, social, economic, and cultural milieu in which both the doctor and patient exist: it is a shared creation.1(162)

Describing diagnosis as a “creation” that develops in the real world, within a context of complex relationships, Hodges reminds us that diagnosis is often far from cut and dried, offering continual opportunities for refinement and improvement.

Researchers from the University of California in San Francisco recently proposed a model of four categories for calibrating the relationship between diagnostic certainty and accuracy.15 Their model encompasses “slam dunk” diagnoses that are clearly accurate and certain, through some that are accurate but uncertain, inaccurate and uncertain, to the inaccurate and certain category they call “diagnostic hubris.”15(123) They offer the model as a tool to help medical educators begin “important conversations [with trainees] about issues that are often left unspoken.”15(123) The awareness and transparency their model provides about degrees of certainty might also help future conversations about MUS and the issues it raises for patients and clinicians alike.

Thank you to our reviewers: Jeannine Cyr Gluck, MLS; Mark L. Graber, MD; Michael Grossman, MD; and Lorri Zipperer, MA.

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