Complete Blood Count (CBC)

A complete blood count (CBC) is a blood test that measures the number of different types of blood cells in a sample of your blood.

Red blood cells (also called RBCs and erythrocytes) contain the protein hemoglobin, which carries oxygen from the lungs to the rest of the body. Having low red blood cells is called anemia.

blood count chart

Platelets (also called thrombocytes) help form blood clots to slow or stop bleeding and to help wounds heal. Having low platelets is called thrombocytopenia (THROM-boh-sy-toh-PEE-nee-uh). This makes it hard for your blood to clot and easy to develop bleeding and bruising.

platelet chart

White blood cells (also called WBCs and leukocytes) are part of the body’s immune system. They help the body fight infection and other disease. Having low white blood cells is called leukopenia (LOO-koh-PEE-nee-uh) and makes it hard for your body to fight off infection.

white blood cell chart

*Since normal ranges vary somewhat from lab to lab, use your lab’s normal ranges if they are reported with your results, instead of the numbers above.