A high anion gap is most often seen in metabolic acidosis. The anion gap is the difference between the concentration of unmeasured anions and unmeasured cations in plasma and can be calculated from the serum levels of chloride, sodium, potassium, and bicarbonate ions. Normal values range from 8 to 16 mmol/L, with a mean value of 12 mmol/L. If the anion gap is greater than 16 mmol/L, it is an elevated anion gap, which is common in metabolic acidosis, seen in patients with diabetes mellitus and uremia. In diabetic ketoacidosis, acidosis occurs due to the accumulation of ketone bodies as a result of impaired glucose metabolism, increased lipolysis in the body, and decreased ability of the liver to utilize them. Metabolic acidosis caused by uremia, when renal failure, acidic metabolites retained in the body in large quantities. In addition, long-term heavy drinking can cause ethanol ketoacidosis, large amounts of diarrhea or vomiting caused by the loss of digestive juices, alkali excretion increased after the cause of metabolic acidosis. When metabolic acidosis occurs, it is necessary to complete the examination as soon as possible to clarify the cause of the disease, according to the type of metabolic acidosis to give active treatment, through the infusion treatment to correct the water and electrolyte disorders, to correct metabolic acidosis.