Extract:In our collective enthusiasm to diagnose and treat disease, a growing body of evidence indicates that we may often be doing too much of a good thing. “Overdiagnosis” is now widely recognised to occur when people are labelled with or treated for a disease that would never cause them harm—often as a result of undergoing screening—and it can lead to the overuse of further tests and treatments. One example is thyroid cancer,with estimates that over 500 000 people may have received overdiagnoses across 12 countries in the past two decades, leading to unnecessary surgery and lifelong medication for many. Overdiagnosis is a challenge to the sustainability of human health and health systems. Its causes—including the best of intentions—are as complex and multifaceted as the potential solutions. As part of the preparation for a possible national action plan in Australia, we searched the literature for causes of and responses to overdiagnosis. Here we provide the first comprehensive analysis of the possible drivers of overdiagnosis and related overuse, mapped to potential solutions.