Emergency physicians face a diagnostic challenge unlike any other in medicine. Patients arrive unannounced, often unable to provide coherent histories, with conditions ranging from trivial to immediately life-threatening. Decisions must be made quickly, often with incomplete information. In this environment, misdiagnosis happens—and when it does, the consequences can be severe.
Why ER Misdiagnosis Happens
The emergency department is a perfect storm for diagnostic error. Time pressure means physicians can't order every test or pursue every possibility. Patients may be poor historians—intoxicated, confused, in too much pain to communicate clearly, or simply unaware of their own medical histories. Prior records may not be available. The parade of patients with minor complaints creates a baseline expectation that most presentations will turn out to be benign.
Cognitive biases flourish in this environment. Anchoring leads physicians to lock onto initial impressions and resist changing course when new information suggests they're wrong. Availability bias makes recently seen conditions seem more likely. Attribution bias leads to dismissing symptoms in certain patient populations—the psychiatric patient whose chest pain gets written off as anxiety, the frequent flyer assumed to be seeking drugs, the elderly patient whose confusion gets attributed to baseline dementia.
System factors compound individual cognitive errors. Overcrowding creates pressure to disposition patients quickly. Inadequate staffing means less time per patient. Communication breakdowns between shifts lose critical information. Test results that return after discharge may never be acted upon.
High-Stakes Misses
Some conditions are missed more often than others, and some misses carry particularly devastating consequences. Heart attacks in patients with atypical presentations—women, diabetics, younger patients—are frequently misdiagnosed as anxiety, GI problems, or musculoskeletal pain. Strokes presenting with dizziness or subtle neurological changes get labeled as inner ear problems or migraines. Meningitis in its early stages looks like flu. Appendicitis can present atypically and be dismissed as gastroenteritis. Pulmonary embolism, ectopic pregnancy, and aortic dissection all have presentations that can mimic less dangerous conditions.
These high-stakes conditions share characteristics that make them easy to miss: they can present atypically, they can look like more common and less dangerous conditions, and they can deteriorate rapidly when not diagnosed and treated promptly. Emergency physicians must maintain high suspicion for these diagnoses even when initial presentation suggests something benign.
The Standard of Care Question
Emergency medicine malpractice doesn't require that physicians make correct diagnoses in every case. The standard is what a reasonably competent emergency physician would do under similar circumstances—which acknowledges the constraints of emergency practice.
What the standard does require is appropriate clinical reasoning. Dangerous conditions should be considered in the differential diagnosis when presentation warrants. Testing should be sufficient to rule out serious possibilities before attributing symptoms to benign causes. When clinical features suggest a serious condition, that condition should be actively excluded rather than dismissed based on impression.
A missed diagnosis becomes malpractice when the physician failed to consider possibilities they should have considered, failed to order tests that would have revealed the true diagnosis, or failed to respond appropriately to clinical features that should have raised suspicion. The question isn't whether the diagnosis was correct, but whether the diagnostic process met professional standards.
Proving ER Misdiagnosis
Medical records document the clinical information available to the physician: vital signs, reported symptoms, physical examination findings, test results. They also document the physician's thinking: what diagnoses were considered, what was ruled out and how, what the assessment and plan were. Comparing this documentation to what the standard of care required reveals where reasoning may have failed.
Expert testimony is essential. A qualified emergency physician reviews the case, considers what a competent peer would have done with the same information, and explains how the defendant's approach fell short. Without this expert analysis, juries have no basis for evaluating whether care was negligent.
Causation requires showing that correct diagnosis would have changed the outcome. If your condition would have progressed identically regardless of earlier diagnosis, misdiagnosis didn't cause legally compensable harm. The value of misdiagnosis claims depends on how much earlier detection would have improved your outcome.
What Happens After Misdiagnosis
Patients misdiagnosed in the ER typically return sicker than they left. The bounce-back visit—often to the same emergency department—finds a condition that has progressed, sometimes past the point where optimal treatment is possible. What could have been caught and treated on the first visit now requires more aggressive intervention with worse expected outcomes.
Some patients don't make it back. They die at home, or arrive in cardiac arrest, or suffer strokes that leave them unable to communicate what happened. In these cases, family members may bring wrongful death claims on their behalf, seeking accountability for the missed opportunity to save a life.
Reducing Misdiagnosis Risk
Patients can't control emergency physician decision-making, but they can advocate for themselves. Clearly communicating symptoms and their progression helps ensure physicians have accurate information. Asking directly what diagnoses have been considered and ruled out can prompt more systematic thinking. Expressing concern about discharge if symptoms haven't improved may lead to additional evaluation. None of this guarantees correct diagnosis, but it may reduce the risk of dangerous cognitive shortcuts.