NCIt definition : A product of hemoglobin produced by oxidation of the iron atom from the ferrous to
the ferric state.;
Alternative definition : NCI-GLOSS: A form of hemoglobin found in the blood in small amounts. Unlike normal
hemoglobin, methemoglobin cannot carry oxygen. Injury or certain drugs, chemicals,
or foods may cause a higher-than-normal amount of methemoglobin to be made. This causes
a condition called methemoglobinemia.;