What Is a Second Opinion and When to Get One?

A medical second opinion — having another qualified physician independently evaluate your diagnosis and treatment plan — is one of the most powerful tools patients have for ensuring they are receiving accurate, appropriate care. Yet many patients hesitate to seek second opinions, fearing they will insult their doctor, appear to distrust the medical system, or delay care unnecessarily. Understanding when second opinions are appropriate, what the evidence shows about their impact, and how to seek one effectively removes these barriers.

Why Second Opinions Matter

Diagnostic error is a significant and underappreciated problem in medicine. A landmark 2015 National Academy of Medicine report found that approximately 5% of adults who seek outpatient care each year experience a diagnostic error — and that most people will receive at least one wrong diagnosis in their lifetime. A 2019 study found that 21% of patients who sought a second opinion at Mayo Clinic had their diagnosis completely changed, and an additional 66% had their diagnosis refined or modified.

For complex or serious diagnoses, the stakes of a missed or incorrect diagnosis are high. A second opinion provides a verification layer — a second set of expert eyes evaluating the same information and potentially bringing different experience, institutional resources, or subspecialty expertise.