In acute pancreatitis, serum amylase starts to rise after the onset of pancreatitis. Serum amylase is a type of pancreatic enzyme that starts to rise a few hours after the onset of pancreatitis, peaks at 24 hours, and gradually decreases to normal after 4-5 days. It may last 1-2 weeks. If the serum amylase is elevated, but the serum amylase isoenzyme is not high, it is not possible to diagnose acute pancreatitis, but it may be caused by other acute abdominal conditions, such as acute appendicitis, intestinal obstruction, cholecystitis, etc. Another point to note is that the higher the amylase value, the more accurate the diagnosis of acute pancreatitis. The higher the amylase value, the greater the accuracy of acute pancreatitis, but the magnitude of the elevation and the severity of the lesion are not positively correlated.