Lipase (and Amylase)

Reference ranges

Severity and critical values

Conversion: Nothing to convert. Enzyme activity is reported in U/L.

High (above 3 times ULN, with pain or imaging)

High amylase without pancreatitis

Amylase also rises with macroamylasemia, a decreased glomerular filtration rate and salivary gland disease. Extrapancreatic inflammation does too, from appendicitis and cholecystitis to intestinal obstruction or ischemia, peptic ulcer and gynecologic disease.

Low values

A value below the ULN does not rule out acute pancreatitis. It is most often a false negative when the sample is drawn late. Work through the interpretation steps before you rule the diagnosis out.

Step-by-step approach

1. Is the pain consistent? Typical pain is constant. It sits in the epigastric or left upper quadrant and radiates to the back, chest or flanks. Dull, colicky or lower abdominal pain points somewhere else.
2. Are two of three criteria present? Pain, lipase or amylase above 3 times ULN, and characteristic imaging.
3. How sick is the patient now? Look for organ failure or SIRS. Either one means a monitored bed.
4. What is the cause? Check gallstones, alcohol, triglycerides, recent ERCP and medications.
5. Grade severity and set the disposition. Use the Atlanta classes below. Trend the BUN and hematocrit rather than relying on one value.

Diagnosis: two of three criteria

Lipase vs amylase

Accuracy at 3 times ULN

A 2017 Cochrane review pulled 10 studies, covering 5,056 people with acute abdominal pain in the emergency department. For lipase above 3 times normal, the pooled sensitivity was 0.79 (95% CI 0.54–0.92) and specificity 0.89 (95% CI 0.46–0.99). Here's the catch: one study, which supplied about two-thirds of the participants, was left out of the pooled analysis because of major concerns about its participants. So these estimates rest on far fewer people. The data were sparse, and risk of bias was unclear or high in every included study.

Amylase above 3 times normal gave similar numbers (sensitivity 0.72, specificity 0.93). Lipase is not clearly better on this evidence. At a sensitivity of 0.79, about one in five people with pancreatitis would be missed, and the confidence interval is wide. About one in ten people without it would be labelled positive.

Severity (revised Atlanta classification)

In the ACG 2024 guideline's wording, organ failure means shock (systolic BP <90 mm Hg), PaO₂ <60 mm Hg, renal failure (creatinine >2 mg/dL after rehydration), GI bleeding >500 mL/24 hours, or a modified Marshall score of 2 or more in one of the three accepted organ systems. The Atlanta source text was not read for this page. If your local criteria differ, use them.

Imaging and scores

• CT timing: Early routine CT does not grade severity, so you do not need it for that. Reserve it for diagnostic doubt, or for no improvement within 48–72 hours of admission and IV hydration.
• Scores: Don't lean on scores or imaging alone to predict moderately severe or severe disease. Neither is accurate enough by itself.
• Risk factors: Risk climbs with an elevated BUN, a high hematocrit, obesity, comorbidity and SIRS.

Medications and analgesia

The 2026 European pain guideline favors the numerical rating scale. It suggests against routine epidural analgesia until better evidence exists. Patient-controlled analgesia gets a caution.

Enteral nutrition

• Mild pancreatitis: Start oral feeding early, within 24–48 hours as tolerated. Use a low-fat solid diet, not a stepwise liquid progression.
• Moderately severe or severe: Enteral feeding cuts infectious complications.
• Route: Nasogastric is preferred over nasojejunal, since safety and efficacy are comparable. Continuous feeds beat bolus.
• Parenteral: Avoid it unless the enteral route is not possible, not tolerated, or not meeting needs.

Infection and necrosis

• Prophylaxis: Don't reach for prophylactic antibiotics in severe pancreatitis. The guideline does not suggest them.
• Infected necrosis: Pick antibiotics that penetrate necrosis. Where possible, delay drainage or debridement beyond 4 weeks.
• Sampling: The guideline suggests against fine-needle aspiration for suspected infected necrosis.

Biliary pancreatitis and ERCP

• Cholangitis: Early ERCP within 24 hours.
• No cholangitis or jaundice: If you suspect a bile duct stone, use MRCP or EUS before ERCP. Medical therapy is suggested over early ERCP within 72 hours.
• Mild gallstone pancreatitis: Plan an early cholecystectomy, preferably before discharge. After a second episode with no cause, cholecystectomy is suggested in fit patients.
• Post-ERCP prevention: ACG 2024 strongly recommends rectal indomethacin for patients at high risk of post-ERCP pancreatitis. The dose is a single 100 mg, given before or immediately after ERCP, with periprocedural intravenous hydration. ACG suggests a pancreatic duct stent in high-risk patients who receive it. Avoid indomethacin with a history of asthma, urticaria or allergic reactions to aspirin or NSAIDs. Use caution with renal impairment, hypovolemia or GI bleeding. Dose per local protocol.

Hypertriglyceridemia

Treat it as acute pancreatitis first. Check triglycerides as a possible cause, preferably when above 1,000 mg/dL. The lipid-lowering plan lives on the triglycerides page.

Doses vary by protocol. Doses are typical references. Follow local protocols, medical direction and institutional policy.

Point-of-care testing

Lipase is a lab assay, and no point-of-care version was verified for this page. Out in the field, you decide on pain, vomiting, and any history of gallstones, alcohol or known hypertriglyceridemia. The number does not make the call.

Before and during interfacility transport

• Obtain: Time of symptom onset, lipase result, BUN and hematocrit. Triglycerides when there are no gallstones or alcohol history.
• Fluids: Continue isotonic crystalloid per protocol. Watch for volume overload in patients with heart or kidney disease.
• Oral intake: Mild disease is where early feeding is favored. Whether to order NPO is a protocol decision.
• Analgesia: Do not withhold opioids for severe pain. Monitor sedation and breathing after each dose.
• Redirect: Organ failure or SIRS needs a monitored bed. Cholangitis needs ERCP within 24 hours. Confirm the receiving center can do it.

Collection and timing

Physiologic and biologic

Common misinterpretations

• "Amylase is normal, so this is not pancreatitis." A normal amylase can miss it, and that is a false negative.
• "Pain location predicts severity." Pain intensity and location do not track severity.
• "Lipase is high, so the cause is alcohol." Gallstones, triglycerides and recent ERCP still need checking.

What it measures

Serum lipase comes from the pancreas, and it is the lab test to lean on for acute pancreatitis. Amylase is the older partner. It stays on this page for comparison.

Physiology & regulation

• Amylase and lipase are the pancreatic enzymes you use to diagnose acute pancreatitis.
• Lipase breaks down dietary fat (triglycerides).
• Lipase is the more specific of the two, and it stays elevated longer.
• Salivary gland disease can also push amylase up.
• The enzyme level does not measure severity. Severity comes from an organ failure assessment.

How it is measured

Your lab sets the sample type, serum or otherwise. Results are reported in U/L against an assay-specific ULN, so take the ULN from your report. Draw at presentation and repeat as the course requires.

Why it matters

The enzyme is one of three criteria for acute pancreatitis, and it does not stand alone. A high value still needs pain and imaging behind it. A normal value does not exclude the diagnosis.