An amylase blood test measures the concentration of the enzyme amylase circulating in the bloodstream. This test helps medical professionals assess the function of specific organs, particularly the pancreas. By quantifying this digestive enzyme, the test provides clues about possible health issues. Significant deviations from the normal range often signal an underlying medical condition requiring further investigation.
The Role of Amylase in the Body
Amylase is a digestive enzyme. Its primary function is to break down complex carbohydrates, specifically starches, into simpler sugars like maltose and glucose. This process begins the chemical digestion of starches, making the resulting sugars available for the body to use as energy.
The body produces amylase in two main locations: the salivary glands and the pancreas. Salivary amylase begins the breakdown of starches as soon as food is chewed. Pancreatic amylase is secreted into the small intestine, where it continues the digestion of carbohydrates. A small amount of this enzyme naturally enters the bloodstream as part of normal biological turnover.
Medical Reasons for Testing
A healthcare provider typically orders an amylase blood test when a patient exhibits symptoms suggesting a problem with the pancreas or salivary glands. The most frequent reason is to help diagnose or monitor acute pancreatitis, which is a sudden inflammation of the pancreas. Symptoms that may prompt the test include severe, sudden upper abdominal pain that may spread to the back, along with nausea, vomiting, or fever.
The test is also used to evaluate chronic pancreatitis, a long-term inflammation that progressively damages the organ. It may also be ordered when conditions such as gallstones, mumps, pancreatic cancer, or a perforated peptic ulcer are suspected, especially to check for pancreatic involvement.
Understanding Your Amylase Results
The normal range for amylase in a blood sample generally falls between 30 and 110 units per liter (U/L). This reference range can vary slightly between different laboratories based on their testing methods. Results are interpreted alongside a patient’s physical symptoms and the results of other blood work, such as a lipase test.
Elevated amylase levels, known as hyperamylasemia, often point toward acute pancreatitis, where levels can rise significantly within hours of inflammation starting. High levels can also signal a blockage in the pancreatic duct, potentially caused by a gallstone or a tumor. Other conditions that may cause temporary elevation include mumps, appendicitis, or a ruptured ectopic pregnancy.
A low amylase level is less common, but it suggests extensive damage to the amylase-producing cells in the pancreas. This finding is associated with severe, chronic pancreatitis, where the pancreas can no longer produce adequate amounts of the enzyme. Low levels may also be seen in cases of severe liver disease or kidney failure, as the kidney is partially responsible for clearing amylase from the blood.
Factors Affecting Results
Several factors can affect the amylase concentration in the blood, potentially leading to inaccurate interpretation. Certain medications, including some pain relievers, corticosteroids, or oral contraceptives, can increase amylase levels. A rare, non-disease state called macroamylasemia occurs when amylase binds to other proteins, forming large complexes that are cleared slowly by the kidneys, leading to inflated measurements. Patients should inform their doctor about all current medications and supplements before the test.