Doctors may administer amylase tests to check for digestive problems or other concerns such as pancreatitis. Testing often occurs by taking a blood or a urine sample to measure levels of amylase, which is an enzyme that normally breaks down carbohydrates in the body for energy. The salivary glands and the pancreas help to produce normal levels of amylase. Test levels range from normal to low to high. While the patient does not need to take special dietary precautions, doctors recommend avoiding alcohol or certain drugs before taking the blood or urine tests because they can interfere with the results.
Sometimes, an inflamed or an unhealthy pancreas causes amylase to filter out into the blood, indicating the need for a test to measure the enzyme's levels. The doctor may give a blood amylase test to check for inflammation of the pancreas, also known as pancreatitis, as well as for pancreatic cysts and gallstones. During the test, the doctor starts by applying antiseptic to the arm area, then wrapping an elastic band around the upper arm to make it easier to draw blood from the lower arm. The patient gets a needle injection into the vein with a tube attached to collect the blood. The doctor removes the needle and the band, and stops the bleeding by covering the injection site with a gauze and bandage.
The urine amylase test provides another method of checking for pancreatitis or other signs of serious conditions, such as pancreatic cancer, pelvic inflammatory disease, or an intestinal obstruction. Two of these types of amylase tests exist, including the two-hour urine sample and the 24-hour collection. For the two-hour test, the patient receives a special container, as well as instructions for collecting the urine sample, which must be done in a two-hour period. Like the two-hour urine amylase test, the 24-hour version requires the use of a special container into which the patient empties his or her bladder. In this case, the patient collects samples, as instructed by the doctor, at specific intervals throughout the day.
Results for the amylase tests usually become available after 48 to 72 hours. According to medical experts, normal levels may vary from one lab to another and range from 23 to approximately 85 units per liter. Lower levels may indicate kidney disease, pancreatic cancer, or preeclampsia in a pregnant woman. Higher levels of amylase may indicate gastroenteritis, acute pancreatitis, or an intestinal blockage.
Advanced preparation is usually unnecessary for both the blood and urine amylase tests, but doctors advise against eating or drinking anything other than water a few hours beforehand. For instance, the patient should avoid drinking alcohol or taking any prescription medications a day before the blood test because they may affect the results. One medical resource notes that birth control pills, opiates like morphine or codeine, and aspirin may spike amylase levels. For the two-hour and 24-hour urine amylase tests, the patient should continue to drink water to collect adequate samples as well as avoid dehydration.