A normal range is 4.1 to 5.9 million per mL. RBC (red blood cells): These blood cells carry oxygen throughout the body. A normal range is 4,500 to 11,000 cells per mL. WBC (white blood cells): These blood cells help fight infection. The numbers on a CBC that providers usually pay most attention to include: It can also be helpful in diagnosing things like infections, blood diseases, and immune system disorders. It’s one of the most common blood tests and is usually a part of routine lab work. A CBC measures the different types of cells in the blood.
