Complete blood count (CBC) is a blood test used to evaluate your overall health & wellness and detect a wide range of disorders like anemia, infection and leukemia. This test measures several components and features of your blood like Red blood cells which carry oxygen; White blood cells which fight infection; Hemoglobin the oxygen carrying protein in red blood cells; Hematocrit proportion of red blood cells to the fluid component or plasma in your blood; Platelets which help with blood clotting. Abnormal increases or decreases in cell counts as revealed in a Complete blood count may indicate that you have an underlying medical condition that calls for further evaluation. This test also helps to monitor a known medical condition.