Why Does Blood Turn Green: Sulfhemoglobinemia

An organism's blood color depends on the type of respiratory pigment present in it. We all know that our blood is red in color because of the presence of hemoglobin in the blood. Hemoglobin is a respiratory pigment that contains a red-colored compound called heme.

Heme is the molecule that transports oxygen from your lungs to all other parts of the body. Normally blood doesn't turn green. But if you have green blood in your body, you may have a rare medical condition called sulfhemoglobinemia.

 This wonderful phenomenon occurs when a hemoglobin molecule integrates a sulfur atom into its structure and changes into sulfhemoglobin. Hemoglobin contains an iron atom to attach to oxygen. 

In the sulfhemoglobin condition, the atom of sulfur blocks the iron from binding to oxygen. This iron-oxygen bonding makes our blood appear red. In a sulfhemoglobin condition, blood appears green or even blue or dark. 

Patients suffering from sulfhemoglobin exhibit a blueish color to their skin. This is caused by the cells and tissues on the periphery of their body parts, like the fingertips, not receiving enough oxygen. This is due to because sulfhaemoglobin can’t transport oxygen like hemoglobin can.

This rare medical condition is caused by excessive exposure to sulfur-containing compounds. Excessive exposure to medications like sumatriptan or furosemide that contain sulfonamides. sulfhemoglobinemia can also be caused by overconsumption of nitrogenous vegetables like spinach usually in early childhood.

According to experts, it takes a huge quantity of these compounds to cause sulfhemoglobinemia. Therefore, you aren’t risking anything by taking your prescribed medications. Sulfhemoglobin treatment is simple, just wait it out. The natural lifespan of red blood cells or erythrocytes is 120 days. 

After 120 days red blood cells are broken down and their components are recycled. So, after about 120 days, all red blood cells containing sulfhemoglobin will have converted to normal red blood cells, and all green coloration of the blood will disappear.