{Reference Type}: Case Reports {Title}: Exploring the Possible Link Between Diabetic Ketoacidosis, Glucose-6-Phosphate Dehydrogenase Deficiency, and Methemoglobinemia. {Author}: Alsubaie HA;Alsubaie GA;Almusalami AM; {Journal}: Cureus {Volume}: 16 {Issue}: 6 {Year}: 2024 Jun 暂无{DOI}: 10.7759/cureus.61656 {Abstract}: One of the most widespread enzymopathies affecting human beings is glucose-6-phosphate dehydrogenase (G6PD) deficiency, which is brought on by inherited mutations in the X-linked gene. Red blood cells (RBCs) with a G6PD deficiency are more sensitive to oxidative assault and consequently to hemolysis. There are more than 200 known G6PD mutations, of which around half are polymorphic and thus prevalent in a variety of populations. We present a case of diabetic ketoacidosis (DKA), with severe hemolytic anemia and methemoglobinemia. The patient was admitted to the intensive care unit, treated for DKA, and received a blood transfusion. In addition, the patient presented with high methemoglobin levels and features of severe hemolytic anemia from the onset, which made the diagnostic consideration of G6PD highly likely. Accordingly, the patient was treated with several doses of ascorbic acid instead of methylene blue. In a nutshell, a patient with DKA who has hemolytic anemia has to have it properly evaluated and controlled. The link between methemoglobinemia, G6PD deficiency, and DKA should be recognized by medical professionals, particularly when oxygen saturation gaps are found.