What is Complete Blood Count (CBC)?

The most common blood test, a Complete Blood Count (CBC), is done to get information on the number of red, white and platelet cells in the blood. It tells your medical team the state of your health.

  • The red blood cell (RBC) count provides information about hemoglobin (the oxygen-carrying protein in RBCs) hematocrit (the amount of space RBC’s take up), reticulocyte (how many young RBCs are there), and the Mean Corpuscular Volume (MCV) (average size of RBCs). It shows how well oxygen is traveling from the lungs to the rest of your body.
  • The white blood cell (WBC) count provides information about leukocytes and other WBCs in the blood. WBCs help the body fight infection. An abnormal WBC count may mean there is an infection, inflammation, or other stress in the body.
  • The platelet count shows if person is in danger of bleeding too much. Platelets are the smallest blood cells, and they support blood clotting to stop bleeding. When a blood vessel is damaged or cut, platelets plug the hole by clumping together. If the platelet count is too low, there is a high risk of bleeding somewhere in the body.