What is pancreatitis and why is it so scary? The most dangerous form of pancreatitis is acute pancreatitis. Acute pancreatitis is an inflammatory reaction in which the pancreatic tissue digests itself, edema, bleeding and even necrosis, caused by the activation of pancreatic digestive enzymes in the pancreas due to various reasons. The main functions of the pancreas are endocrine and exocrine, endocrine is the insulin and other hormones such as glucagon and growth inhibitory hormone that people know, while exocrine is the digestive enzymes of the pancreas, including lipase, amylase and protease, especially protease, which plays a very bad role in the occurrence of pancreatitis. Under normal circumstances, the digestive enzymes of the pancreas are collected through the pancreatic ducts inside the pancreas and then secreted into the duodenum through the duodenal papilla. Before entering the duodenal papilla, the pancreatic duct has to pass through a section called “pot belly”, which is the confluence of bile duct and pancreatic duct, where the pancreatic duct and bile duct converge into the duodenum together. Pancreatic enzymes play a very important role in the digestion of food, if the pancreas has been operated or patients with chronic pancreatitis, pancreatic enzymes are not secreted enough, there will be symptoms of indigestion, even if other digestive enzymes are normally secreted, oral pancreatic enzyme preparations are needed to promote the digestion of food. Pancreatic enzymes have a strong digestive power, so won’t the pancreas be digested by itself? Under normal conditions, pancreatic enzymes are stored in the pancreas in the form of zymogens, which are secreted into the intestine and activated before they exert their digestive effects. Under abnormal physiological conditions, such as heavy drinking and overeating, especially after a high-fat diet, the secretion of gastric acid and duodenal pancreatic hormone increases, and due to the body’s own neuroendocrine regulation, the secretion of pancreatic juice increases, causing the internal pressure of the pancreatic duct to rise, which, together with many other factors, induces the activation of pancreatic enzymes in the pancreas, resulting in acute pancreatitis. In some cases, vomiting after drinking alcohol can cause the Oddi’s sphincter at the opening of the duodenal papilla to contract, leading to the reflux of bile into the pancreatic duct and further promoting the activation of pancreatic enzymes. In addition to overeating, another cause of acute pancreatitis is pancreatitis caused by cholelithiasis, which is caused by stones in the common bile duct blocking the common pathway between the bile duct and the pancreatic duct, promoting the reflux of bile into the pancreatic duct. Acute pancreatitis is characterized by acute upper abdominal pain, nausea, vomiting, fever and increased blood pancreatic enzymes. The extent of the lesions varies, with pancreatic edema predominating in the milder cases, which is clinically common and often self-limiting, with a good prognosis. In a few severe cases, the pancreas is hemorrhagic and necrotic, often secondary to infection, peritonitis and shock, with a high mortality rate, called severe pancreatitis. Clinicopathology often divides acute pancreatitis into two types: edematous and hemorrhagic-necrotic. The death rate of hemorrhagic-necrotic pancreatitis used to be about 50%, and treatment is often nine-death, often requiring surgery. Even after successful treatment, patients often have a lot of problems that affect their quality of life later in life because they turn into chronic pancreatitis or develop pseudocysts of the pancreas. Due to the advancement of medical technology, including the development of drugs and the improvement of the level of critical care medicine, although the death rate is now lower than before, it is still a very critical clinical condition in severe pancreatitis, and doctors are powerless if treatment is not timely.