Acute pancreatitis: Sudden inflammation of the pancreas. The pancreas abruptly becomes inflamed and then gets better. Some people have more than one attack but recover fully after each one.
The cause of acute pancreatitis is most often alcohol abuse or gallstones. Other causes include use of prescribed drugs, trauma or surgery to the abdomen, or abnormalities of the pancreas or intestine. In rare cases, the disease may result from infections, such as mumps. In about 1 case in 6 or 7, the cause is unknown.