Test Overview
A bicarbonate (HCO3) test measures the level
of bicarbonate in the blood. Bicarbonate is a chemical
that keeps the
pH of blood from becoming too
acid. If the pH level drops, HCO3 is
absorbed by the kidneys and returned to the blood instead of passing out of the
body in the urine.
Bicarbonate is not usually tested by itself.
It may be done on a blood sample taken from a vein as part
of a panel of tests that looks at other
electrolytes, such as sodium, potassium, and
calcium. It is often done along with a carbon dioxide test or as
part of an
arterial blood gas (ABG) test. For an arterial blood
gas study, the blood sample is taken from an artery.