The blood test for lipase may be used along with a test for amylase to help diagnose pancreatitis (inflammation of the pancreas) and other pancreatic diseases. It is also used to a lesser extent in the diagnosis and follow-up of cystic fibrosis, coeliac disease, and Crohn's disease.

A lipase test may be used if you show symptoms of a pancreatic disorder, such as severe abdominal pain, fever, loss of appetite, or nausea and to monitor the effect of treatment.

Normal values for lipase depend on the test used to measure it. In acute pancreatitis, lipase levels are very high, often 2 to 5 times normal. Slightly high lipase values may occur in other conditions such as kidney disease, salivary gland inflammation, or peptic ulcer disease. Occasionally lipase is high due to a tumour (cancer). A rapid and sharp rise of lipase in the blood within hours after the beginning of an attack, and a decline after about 4 days, usually indicates acute pancreatitis.

In acute pancreatitis, the changes seen in lipase levels are usually similar to those of another pancreatic enzyme called amylase, but remains elevated longer (for 5 to 7 days).

Lipase and amylase are sometimes used together to diagnose acute pancreatitis. Either lipase or amylase levels may be requested to help diagnose acute pancreatitis.  Either test may also be used to monitor chronic pancreatitis. They may be moderately elevated in chronic pancreatic disease but levels can fall if the cells that produce amylase and lipase in the pancreas become damaged or destroyed. Drugs that may interfere with maintaining proper lipase levels include codeine, indomethacin and morphine.