Platform
Company
Immunology & Autoimmune
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Currently under review
Pending specialist review and validation.
A Gastrin Level test measures the amount of the hormone gastrin in your blood. Gastrin is made by cells in the lower stomach and upper small intestine. It signals your stomach to produce acid for digestion and helps maintain the health of the stomach lining.
This test is typically performed on a fasting blood sample because eating naturally raises gastrin. It is used along with your symptoms, medication history, and sometimes additional stomach acid assessments to evaluate how well your body regulates acid production.
Abnormal gastrin levels can indicate problems with acid regulation in the stomach. Markedly increased levels may occur with gastrin-producing tumors, long-term acid suppression, chronic inflammation of the stomach lining, or low acid states. Low or inappropriately normal levels in someone with symptoms may point to other causes of acid-related problems.
Clinicians order this test for recurrent or hard-to-treat ulcers, unexplained chronic diarrhea, abdominal pain, vitamin B12 deficiency due to certain types of anemia, or after stomach surgery. Results can guide decisions about imaging, endoscopy, testing for specific infections, vitamin levels, and safe adjustments to acid-suppressing medicines.
Your clinician will interpret your result in the context of whether you were fasting, which medications you take, your stomach acid status, kidney function, and other tests. Higher-than-expected results are common with proton pump inhibitors or H2 blockers, with low stomach acid states, Helicobacter pylori infection, chronic atrophic gastritis, pernicious anemia, kidney problems, or a gastrin-producing tumor. A normal result does not exclude disease if you were not fasting or are taking acid-suppressing drugs.
If your result is elevated, your care team may repeat the test under standardized conditions, adjust medications, or order follow-up studies such as gastric pH measurement, a secretin stimulation test, endoscopy, imaging, or vitamin B12 testing. If results are normal or low but symptoms persist, they may look for other explanations. Do not stop or change any medicines without discussing it with your clinician.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Eating, especially protein-rich meals, naturally raises gastrin. A true fasting sample is preferred to avoid a misleadingly high result.
Proton pump inhibitors and H2 blockers can increase gastrin by lowering stomach acid. Your clinician may advise a safe hold before testing.
Low stomach acid and Helicobacter pylori infection can stimulate gastrin release. Treating the underlying condition may normalize levels.
Reduced kidney function can decrease clearance of gastrin, leading to higher measured levels even without increased production.
Procedures such as gastric bypass or vagotomy, and chronic atrophic gastritis, can alter acid feedback and raise gastrin.
Gastrin can fluctuate during the day. Consistent timing and standardized conditions help make results easier to compare.
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