Why do I have to have another blood test regarding cbc? What does this mean? I received a phone call from my doctor regarding my blood results. He wants me to have another test done, but he didn't explain why. Does this have anything to do with the blo

CBC. CBC is a hematology profile blood test that measures red blood cell concentration (hematocrit), white blood cell count and platelet count. It also provides information about the size and shape of red blood cells. This is a routine laboratory test. The most likely reason to repeat the test includes an inadequate specimen (i.e. Not enough blood was obtained in the tube, or a laboratory mishap) or an abnormal result was identified and the physician wants to repeat the test to verify the result. The physician may also ask that the new blood CBC sample include a microscopic exam by a pathologist or technologist in order to visually examine the blood to look for abnormal appearing blood cells or other findings.