Carbon dioxide (CO2) is a waste product made when the body breaks
down food for energy (metabolism). The kidneys and lungs regulate the levels of
carbon dioxide, bicarbonate, and carbonic acid in the blood.
The blood carries carbon dioxide to the lungs, where it is exhaled.
More than 90% of carbon dioxide in the blood exists in the form of bicarbonate
(HCO3). The remainder of the carbon dioxide is either dissolved carbon dioxide
gas (CO2) or carbonic acid (H2CO3).
Last Revised:
November 7, 2011
Author:
Healthwise Staff
Medical Review:
E. Gregory Thompson, MD - Internal Medicine & R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology