The etiology of acute pancreatitis is complex, and the exact cause has not been elucidated so far. A variety of risk factors are known to be involved in the occurrence of acute pancreatitis, and these risk factors vary in different countries and regions. In Europe and the United States, the occurrence of acute pancreatitis is mostly related to alcohol abuse, while in Asia, especially in China, pancreatitis caused by biliary disease is the most common. Clinically, biliary tract diseases and alcoholism constitute 70-80% of the risk factors for acute pancreatitis, while others are related to pancreatic duct stenosis, hyperlipidemia, post-ERCP, infection, trauma, high calcium, drugs, pregnancy, etc. There are still 5-10% of patients who cannot find clear causative risk factors, called idiopathic pancreatitis. The following is an introduction to the common risk factors for acute pancreatitis. 1, biliary tract disorders bile and pancreatic duct “common pathway theory” is the anatomical basis for the occurrence of biliary acute pancreatitis, as early as 1901 Opie found that stones embedded in the lower end of the bile duct cause infectious bile reflux into the pancreatic duct, thus causing acute pancreatitis. In recent years, some authors have proposed the “stone migration theory”, which means that bile duct stones move through the Vater’s jugular, stimulating the mucosa of the jugular and causing papilledema and spasm of the sphincter of Oddi, resulting in the reflux of bile into the pancreatic duct and causing the occurrence of acute pancreatitis. Biliary tract disease is the most common cause of acute pancreatitis in China, accounting for about 50% or more. Bile duct inflammation, stones, parasites, edema, spasm and other lesions cause obstruction in the jugular abdomen, coupled with contraction of the gallbladder, the pressure in the bile duct rises and bile flows back into the pancreatic duct through the common channel, activating pancreatic zymogen and causing pancreatitis due to pancreatic self-digestion. In addition, gallstones, biliary tract infections and other diseases can also cause dysfunction of the sphincter of Oddi, duodenal fluid reflux into the pancreatic duct, activating pancreatic digestive enzymes to induce acute pancreatitis. 2, alcohol Although the mechanism of alcohol-mediated acute pancreatitis is not clear, there is no doubt that alcohol abuse and the occurrence of acute pancreatitis have a clear relationship. Alcoholic pancreatitis can be an acute attack, but most of them are chronic in duration. There is a clear correlation between the development of acute pancreatitis and the amount of alcohol consumed, and the risk of pancreatitis is greatly increased if the intake of alcohol exceeds 420 g per week. In Western countries, alcoholism is the leading cause of acute and chronic pancreatitis. There are 1/2 to 2/3 of acute pancreatitis related to alcoholism in the United States every year. According to foreign data, about 0.9% to 9.5% of alcoholics have clinical-type pancreatitis, and 17% to 45% have evidence of pancreatitis in pathology. Experimental studies and clinical observations have revealed that alcohol may cause acute pancreatitis through the following pathways: first, it stimulates G-cells in the gastric sinus to secrete gastrin and increase gastric acid secretion, which in turn causes acidification in the duodenum, prompting increased secretion of glucagon; second, it causes increased pressure in the duodenum, spasm of the sphincter of Oddi, papillary edema, resulting in increased pressure in the pancreatic duct; third, it affects the exocrine function of the pancreas, and in the pancreatic duct The third is to affect the exocrine function of the pancreas and produce protein deposits in the pancreatic duct, blocking the pancreatic duct and causing pancreatitis. 3, metabolic abnormalities hyperlipidemia increases blood viscosity, serum lipid particles block pancreatic blood vessels, resulting in pancreatic microcirculation disorders, pancreatic ischemia and hypoxia. Hydrolysis of serum triglycerides releases a large amount of free fatty acids with toxic effects, causing the formation of local microembolism and damage to capillary membranes. Hypertriglyceridemia due to multiple causes (such as drugs, diabetes, genetics, pregnancy, and familial hyperceliac disease) has been reported to account for 6.9% of the etiology of acute pancreatitis. Hypercalcemia such as hyperparathyroidism, multiple myeloma, pregnancy or vitamin D toxicity, calcium ions can stimulate pancreatic secretion, activation of pancreatic enzymes, easy to form stones and calcification in the alkaline pancreatic fluid, blocking the pancreatic duct, renal cell carcinoma due to increased levels of parathyroid-like peptide substances can also induce acute pancreatitis. 4, ischemia The pancreas is extremely sensitive to ischemia, and ischemic injury to the pancreas caused by various reasons is a direct factor in the occurrence of acute pancreatitis. In addition to severe hypovolemic shock causing pancreatic ischemia, pancreatic artery embolism and vasculitis triggered by microemboli can also be pancreatic ischemia, infarction, and even acute pancreatitis. Acute pancreatitis caused by ischemia is clinically difficult to diagnose and often misdiagnosed, and should be taken seriously in the differential diagnosis of idiopathic pancreatitis. 5, infection Certain acute infectious diseases such as typhoid fever, scarlet fever, sepsis, etc., serious abdominal infections such as acute biliary tract infections, etc., may become the cause of acute pancreatitis. It is reported that some viruses such as mumps virus, coxsackievirus and cytomegalovirus can also cause acute pancreatitis. 6, surgery and trauma blunt abdominal injury extrusion of the pancreatic parenchyma or pancreatic penetrating injury, laparotomy operation injury to the pancreas, may cause pancreatic fluid overflow or bile intestinal fluid reflux and cause acute pancreatitis. Pancreatitis caused by retrograde cholangiopancreatography (ERCP) accounts for 0.5-5% in clinical practice and is mostly caused by excessive contrast injection or high pressure. Most of the patients belong to the light pancreatitis, mostly can be self-healing; but a small number of patients can develop into heavy pancreatitis, and even cause death, so it should cause clinical attention. 7, drugs Drug-induced acute pancreatitis in recent years in the clinical reports more and more commonly used drugs such as hydrochlorothiazide, glucocorticoids, sulfonamides, azathioprine, warfarin, lamivudine, Stavudine, Indinavir, valproic acid (VPA), statins and other drugs can lead to acute pancreatitis. 8, tumors or parasites benign and malignant tumors near the pancreatic or duodenal papilla compressing the biliopancreatic duct causing obstruction, ischemia or direct infiltration activating pancreatic enzymes can induce acute pancreatitis. Some parasites such as Ascaris lumbricoides and Schistosoma chinensis infection causing biliopancreatic duct obstruction is also a cause of pancreatitis.