Monarch Disease Ontology entry MONDO_0006988 (sulfhemoglobinemia) is a morbid condition due to the presence of sulfmethemoglobin in the blood. It is marked by persistent cyanosis, but the blood count does not reveal any special abnormality in the blood. It is thought to be caused by the action of hydrogen sulfide absorbed from the intestine. (Stedman, 25th ed). Also known as: Sulfemoglobinemia.