25. Methemoglobinemia
The blue skin disorder is characterized by an abnormal amount of methemoglobin, a type of hemoglobin that carries iron in a person’s blood. Most people have 1% methemoglobin in their blood stream, whereas suffers have 10% and 20%. Iron-carrying hemoglobin carries an extremely reduced amount of oxygen, which means patients diagnosed with methemoglobinemia have a higher risk of heart abnormalities.