Amylase is an enzyme found in the pancreas and parotid glands (salivary glands).
If there are no signs or symptoms of parotid inflammation (mumps, etc.), a high level of amylase in the blood generally indicates an inflammatory impairment of the pancreas (due to alcoholism, gallstones, or more rarely following a trauma, viral infection, extremely high calcium or triglyceride levels, a tumour, a drug, etc.). In the case of acute pancreatitis, amylase levels typically rise to as much as 4 to 6 times the normal upper reference limit. This occurs within 4 to 8 hours of onset and returns to normal within a few days when the condition is treated successfully. In chronic pancreatitis, amylase levels tend to return to normal gradually, even if the disease has not disappeared, due to the destruction of the pancreas. It is preferable to measure levels of the lipase enzyme to diagnose and monitor chronic pancreatitis.
In rare cases, high blood levels of amylase can be caused by the presence of macroamylase, a form of amylase that is too big to be eliminated by the kidneys. This condition is harmless and can be confirmed by measuring amylase clearance.