Amylase is the most commonly used clinical indicator for the diagnosis of acute pancreatitis. Blood amylase rises earlier than urinary amylase, and blood amylase often begins to rise 2 to 6 hours after the onset of the disease, reaching a peak in 12 to 24 hours. Patients with mild acute pancreatitis can return to normal after 24 to 56 hours, and no later than 3 to 5 days. However, it should be noted that many acute abdominal conditions are accompanied by elevated blood amylase, including appendicitis, gastrointestinal perforation, cholecystitis, etc. Moreover, the diagnosis of acute pancreatitis cannot be ruled out when patients with acute abdominal conditions undergo blood amylase tests if the results are normal. Therefore, high blood amylase is not necessarily caused by acute pancreatitis. At the same time, some patients with acute pancreatitis do not necessarily have elevated amylase, and the severity of acute pancreatitis is not consistent with the degree of amylase elevation, about half of the patients with acute pancreatitis do not have elevated amylase, the reasons may be 1, amylase has a short half-life and is quickly cleared from the systemic circulation. 2. The pancreas is extensively damaged: for example, in patients with chronic pancreatitis and previous episodes of severe acute pancreatitis, amylase may not be elevated during episodes of acute pancreatitis. Although amylase monitoring is simple and easy, many studies in recent years have found that its diagnostic value is inferior to that of blood lipase. With the advancement of experimental diagnostic techniques, the use of blood lipase testing has been gradually promoted. Therefore, if the conditions of the hospital you visit allow, it is recommended to check blood amylase along with blood lipase, so that the diagnosis of acute pancreatitis can be more accurate.