There is a tendency to overdiagnose acute pancreatitis. A reasonable threshold for a diagnosis of acute pancreatitis is a serum level of amylase (or lipase) that is at least three times the upper limit of the normal range, plus a history of characteristic abdominal pain. If amylase (or lipase) does not reach this threshold, it is best not to make the diagnosis of acute pancreatitis unless findings on computed tomography or MRI reveal characteristic changes of acute pancreatitis.
New England Journal of Medicine - Vol. 359, No. 9, August 28, 2008