An amylase test measures the amount of this enzyme in a sample of blood taken from a vein or in a sample of urine.
Normally, only low levels of amylase are found in the blood or urine. But if the pancreas or salivary glands become damaged or blocked, more amylase is usually released into the blood and urine. In the blood, amylase levels rise for only a short time. In the urine, amylase may remain high for several days.
Why It Is Done
A test for amylase is done to:
- Find pancreatitis and other pancreatic diseases.
- See if the treatment for pancreatitis and other pancreatic diseases is working.
- Check swelling and inflammation of the salivary glands.
How To Prepare
To prepare for an amylase test:
- Do not drink alcohol for 24 hours before the test.
- For a blood test for amylase, do not eat or drink anything except water for at least 2 hours before having the test.
- For a 24-hour urine test for amylase, be sure to drink enough fluids during the test to prevent dehydration.
How It Is Done
A health professional uses a needle to take a blood sample, usually from the arm.
Amylase can be measured in a 24-hour or 2-hour urine sample.
A 24-hour urine sample is all of the urine you produce over a 24-hour period.
- You start collecting your urine in the morning. When you first get up, empty your bladder, but don't save this urine. Write down the time that you urinated to mark the start of your 24-hour collection period.
- For the next 24 hours, collect all your urine. Your doctor or lab will usually provide you with a large container that holds about 1 gal (4 L). The container has a small amount of preservative in it. Urinate into a small, clean container, and then pour the urine into the large container. Do not touch the inside of the container with your fingers.
- Keep the large container in the refrigerator for the 24 hours.
- Empty your bladder for the final time at or just before the end of the 24-hour period. Add this urine to the large container, and record the time.
- Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in the urine sample.
A 2-hour urine sample is all of the urine you produce over a 2-hour period. Collect it in the same manner as the 24-hour urine sample, during the 2-hour period your health professional recommends.
How It Feels
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
This test usually doesn't cause any pain or discomfort.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
There are no known risks from having this test.
Results are normally available within 72 hours.
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
Values may be high because of:
- Inflammation of the pancreas (pancreatitis), a pancreatic cyst, or cancer of the pancreas.
- Inflammation of the salivary glands, such as mumps.
- Blockage of, or severe damage to, the intestines (bowel obstruction or strangulation).
- A stomach ulcer that caused a hole in the stomach wall.
- Gallstones that are causing pancreatitis.
- Diabetic ketoacidosis.
- A ruptured ectopic pregnancy.
- Kidney failure.
- Appendicitis or peritonitis.
- Macroamylasemia, an uncommon and harmless condition in which amylase is bound to a protein in the blood.
Current as of: September 8, 2022
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Kathleen Romito MD - Family Medicine