Serum/plasma mass concentration of Gastrin (fasting)

Why Is This Test Done?

Your doctor may order a fasting gastrin test if you have symptoms like persistent stomach pain, diarrhea, or unexplained ulcers. It’s also used to check for Zollinger-Ellison syndrome, a rare tumor that causes high stomach acid levels, or other conditions like gastroparesis or hyperparathyroidism that may affect hormone balance.

What to Expect Before the Test

You’ll need to fast (no food or drink except water) for 8–12 hours before the test. Avoid smoking and caffeine. Bring any medications to discuss with your provider, as some may affect results.

How the Test Works

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s analyzed for gastrin levels using a specialized immunoassay method to detect hormone concentrations.

What the Results Mean

Results are compared to a reference range for your age and health status. Elevated levels may suggest conditions like Zollinger-Ellison syndrome, while lower levels could indicate stomach issues or other hormonal imbalances. Your doctor will interpret results in the context of your symptoms and medical history.