A complete blood count (CBC) test is a group of tests that provides information about blood cells like red blood cells (RBC), white blood cells (WBC), and platelets. It is routinely performed to provide an overview of a patients general health status. It is the screening tool used to confirm a hematologic disorder, to establish or rule out a diagnosis, to detect an unsuspected hematologic disorder, or to monitor the effects of radiation or chemotherapy. A morphology evaluation is also performed when abnormal results are identified upon microscopic examination.