overdiagnosis

Overdiagnosis is the diagnosis of disease that will never cause symptoms or death during a patient's ordinarily expected lifetime and thus presents no practical threat regardless of being pathologic. Overdiagnosis is a side effect of screening for early forms of disease. Although screening saves lives in some cases, in others it may turn people into patients unnecessarily and may lead to treatments that do no good and perhaps do harm. Given the tremendous variability that is normal in biology, it is inherent that the more one screens, the more incidental findings will generally be found. For a large percentage of them, the most appropriate medical response is to recognize them as something that does not require intervention; but determining which action a particular finding warrants ("ignoring", watchful waiting, or intervention) can be very difficult, whether because the differential diagnosis is uncertain or because the risk ratio is uncertain (risks posed by intervention, namely, adverse events, versus risks posed by not intervening).

Overdiagnosis occurs when a disease is diagnosed correctly, but the diagnosis is irrelevant. A correct diagnosis may be irrelevant because treatment for the disease is not available, not needed, or not wanted. Some people contend that the term "overdiagnosis" is inappropriate, and that "overtreatment" is more representative of the phenomenon.