The blood test for lipase is ordered, often along with an amylase test, to help diagnose and monitor acute pancreatitis (inflammation of the pancreas), chronic pancreatitis, and other disorders that involve the pancreas.

Lipase testing is also occasionally used in the diagnosis and follow-up of cystic fibrosis, celiac disease, and Crohn's disease.

A lipase test may be ordered when a patient has symptoms of a pancreatic disorder, such as severe abdominal pain, fever, loss of appetite, or nausea. It may also be ordered at intervals when a doctor wants to monitor a patient with a pancreas condition to evaluate the effectiveness of treatment and to determine whether the lipase levels are increasing or decreasing over time.

In acute pancreatitis, lipase levels are frequently very high, often 5 to 10 times higher than the highest reference value (often called the upper limit of normal). In acute pancreatitis, lipase concentrations rise within 24 to 48 hours of an acute pancreatic attack and may remain elevated for about 5 to 7 days. Concentrations may also be increased with pancreatic duct obstruction, pancreatic cancer, and other pancreatic diseases.

Moderately increased lipase values may occur in other conditions such as kidney disease (due to decreased clearance from the blood), salivary gland inflammation, a bowel obstruction, or peptic ulcer disease, although the lipase test is not usually used to monitor these conditions. Decreased lipase levels may indicate permanent damage to the lipase-producing cells in the pancreas.

Since the reference values for lipase will vary from laboratory to laboratory, depending on the test method used, there is no universally accepted number that can be called normal or high.

In acute pancreatitis, elevated lipase levels usually parallel blood amylase concentrations, although amylase levels tend to rise and fall a bit sooner than lipase levels. Drugs that may increase lipase levels include codeine, indomethacin, and morphine.