Updated January 19, 2015.

Definition: CBC (Complete Blood Count)

A complete blood count (CBC) is a blood test done to check the levels of certain cells in the blood.  There are many reasons for doctors to check a CBC.   In lung cancer, a complete blood count (CBC) is often checked at the time of diagnosis, and to follow the levels of blood cells during treatment.

A CBC tests:

• The levels of red blood cells (RBCs) - cells that carry oxygen through the body;

• White blood cells (WBCs) - cells that fight infection; and
• Platelets - cells that help blood to clot.

A low level of red blood cells (RBCs) is known as anemia; white blood cells (WBCs), leukopenia; and platelets, thrombocytopenia.