What are the two most common etiologies of acute pancreatitis?

• A. Hyperlipidemia and pancreatic cancer
• B. Hypercalcemia and infections
• C. Gallstones and alcohol
• D. Autoimmune disease and trauma

Answer: (C)

Acute pancreatitis is most often caused by obstruction of the pancreatic duct or by direct injury to the pancreas. The two most common etiologies are gallstones and alcohol use. Gallstones can block the ampulla of Vater, causing bile to reflux into the pancreatic duct and triggering premature enzyme activation within the pancreas, leading to autodigestion and inflammation. Alcohol contributes through direct acinar toxicity, increased enzyme secretion, and ductal changes that promote premature activation of pancreatic enzymes, especially with heavy or chronic intake. Other causes exist—such as metabolic disturbances, infections, autoimmune disease, trauma, medications, and malignancy—but they are less common than gallstones and alcohol.