The abbreviation RBC in blood work refers to red blood cells, notes MedlinePlus. Doctors use the red blood cell count test to determine the number of red blood cells a patient has in the blood. This helps to diagnose anemia and other conditions that affect the red blood cells.
Red blood cells have a component called hemoglobin, which carries oxygen in the body, states MedlinePlus. The number of red blood cells in the blood determines the amount of oxygen the body tissues get and how well they function. The normal range for males is 4.7 to 6.1 million cells per microliter, while for females it's 4.2 to 5.4 million cells per microliter.