The normal value of serum amylase is 35-135 U/L. Amylase is a digestive enzyme that helps digest sugar substances. Amylase in the blood mainly comes from the pancreas and parotid gland. The one from the pancreas is called pancreatic amylase; the one from the parotid gland is called salivary amylase. Other tissues, such as the heart, liver, lungs, thyroid, ovaries, and spleen, also contain small amounts of amylase. Serum amylase levels are increased when problems occur in the pancreas and parotid gland. Serum amylase is measured mainly in patients with abdominal pain to rule out acute pancreatitis or to help diagnose acute pancreatitis, which is the most common cause of elevated serum amylase. Serum amylase is also elevated in mumps, mainly salivary amylase, and serum amylase is also routinely checked in mumps. When the pancreas is affected by a chronic disease, such as chronic pancreatitis or pancreatic cancer, serum amylase can drop due to decreased amylase secretion.