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.