A serum total bilirubin measurement of 39.4 μmol/L may be a sign of a problem in the processes of bilirubin production, metabolism, and excretion. The reference value of serum total bilirubin ranges from 3.4 to 17.1 μmol/L, so 39.4 μmol/L is a sign of elevated total bilirubin. There may be excessive production of bilirubin, such as hemolysis; metabolic abnormalities such as liver dysfunction like cirrhosis; and excretion disorders such as bile duct stones, pancreatic head or bile duct occupancy leading to obstruction of the bilirubin excretion pathway. In addition to measuring the total bilirubin level, further measurements of the levels of conjugated and unconjugated bilirubin are required. If the ratio of conjugated bilirubin to total bilirubin is 20-50%, then hepatocellular dysfunction is considered, while hemolysis is more likely to be considered if the ratio is less than 20%, and impaired excretion due to obstruction is more likely to be considered if the ratio is greater than 50%. To summarize, it is recommended to consult a doctor as soon as possible to further improve the relevant examination to clarify the cause.