Glycolic acid is formed by the combination of bile acid and glycine, and is a bound bile acid. When the liver cells are damaged, the liver’s ability to take up glycolic acid is reduced, or the bile in the liver is stagnant, or the liver’s excretion of hepatic bile acids is impaired, the serum glycolic acid level can be increased. Therefore, the value of serum glycolic acid reflects not only the function of liver cells, but also the function of bile excretion. For example, acute and chronic hepatitis, cirrhosis, alcoholic liver disease, autoimmune liver disease, primary liver cancer, cholelithiasis, bile duct cancer, periampullary cancer and other related diseases can cause an increase in serum glycolic acid values. It is also important to note that serum glycolic acid is an important diagnostic indicator of intrahepatic cholestasis during pregnancy, and the higher the value, the greater the impact on the mother and fetus, which can significantly increase the rate of amniotic fluid contamination, preterm delivery, intrauterine distress and cesarean section. Therefore, serum glycopyrrolate can be used not only as an early predictor of liver damage, but also for clinical prognosis.