The most useful immediate marker of acute pancreatitis is the serum amylase and lipase levels. Serum amylase is an enzyme produced in the pancreas, and an elevated level indicates pancreatitis. Lipase is a digestive enzyme secreted by the pancreas and is also a good marker of acute pancreatitis, when it is present in greater than three times the upper limit of normal. Other markers, such as imaging studies, may be used to confirm the diagnosis, but serum amylase and lipase levels are the most useful immediate markers of acute pancreatitis.