Despite many similarities in training, doctors can differ in their views on how to diagnose or treat certain diseases. Such differences can occur even among the best doctors. Differences often arise because the evidence for the best approach is not clear. Differences in recommendations can also depend on how familiar a doctor is with a test or treatment, how willing the doctor is to use the latest tests and treatments, and how available those tests and treatments are in the community.

For these reasons, getting a second opinion from a different doctor can give a person additional insight and more information about what to do. If the second opinion is the same, it can reassure a person and reduce anxiety. If it is different, the options can be weighed and the result is a more informed choice about what to do. If the second opinion is different from the first, a person may even want to get a third opinion.