Diagnostic test

In medicine, a diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease, injury or any other medical condition. For example, such a test may be used to confirm that a person is free from disease, or to fully diagnose a disease, including to sub-classify it regarding severity and susceptibility to treatment. Companion diagnostics have also been developed to preselect patients for specific treatments based on their own biology, where such targeted therapy may hold promise in personalized treatment of diseases such as cancer.