

CO2 is carbon dioxide. A serum CO2 test measures the amount of carbon dioxide in the liquid part of your blood.
In the body, most of the CO2 is in the form of a substance called bicarbonate (HCO3-). Therefore, the CO2 blood test is really a measure of your bicarbonate level.
See also: Blood gases
Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2