Diagnostic testing refers to a series of medical tests and procedures that are used to identify or diagnose a specific disease, condition or disorder. These tests can be conducted on blood samples, tissue biopsies, urine specimens or other body fluids, depending on the suspected illness. The goal is to gather as much information about the patient's health status and symptoms in order to determine what may be causing their problems. Diagnostic testing can help doctors identify potential medical issues early on, allowing for more effective treatment plans and better outcomes for patients.