When people get full-body scans or lab tests and are told about unexpected results—even if those results might not mean anything—they end up getting more biopsies, especially when the scan findings are shared. This might lead to too many medical tests that aren’t really needed.

When doctors tell patients about unexpected lab results, it leads to 37% more biopsies—but even more biopsies happen when doctors share unexpected MRI results, meaning imaging scans seem to trigger more follow-up tests than blood tests.

When doctors tell patients about unexpected findings on a full-body MRI scan, it leads to over three times more biopsies that find cancer—but even then, very few actual cancers are found, so it might not be worth the hassle and cost.

When people are told about unexpected findings from a full-body MRI scan, they’re much more likely to get unnecessary biopsies that turn out to be harmless — meaning doctors might be doing too many tests that don’t find cancer.

In a study where people got full-body MRI scans for research, about 1 in 3 were told they had some unexpected health finding that might need attention.

When people who’ve had cancer before are told about unexpected health findings from a research study, they’re almost three times more likely to get a biopsy — suggesting that sharing these findings might lead to more testing in people already at higher risk.