Methemoglobinemia, also known as met-Hb, is a disorder characterized by the presence of a higher than normal level of methemoglobin in the blood. Methemoglobin is a form of hemoglobin that doesn't bind oxygen. When its concentration is elevated in red blood cells, anemia and tissue hypoxia can occur. Overview Normally, methemoglobin (methaemoglobin) levels are… (More on Methemoglobinemia)