Hemoglobin: Understanding the Medical Term for Blood Iron

The medical term for the blood iron substance is hemoglobin. Hemoglobin is a complex protein found in red blood cells that carries oxygen from the lungs to the rest of the body, and carbon dioxide from the body tissues back to the lungs to be exhaled. It is composed of four protein subunits, called globins, and four heme groups, each of which contains an iron ion.