The gastrin blood test measures the amount of the hormone gastrin in blood.
How the test is performed
A blood sample is needed.
How to prepare for the test
Certain medicines may affect the results of this test. Your doctor will tell you if you need to stop taking any medicines. Do not stop taking any medicine before talking to your doctor.
Medicines that can increase gastrin measurements include antacids, H2-blocking agents (such as cimetidine), and proton pump inhibitors (such as omeprazole).
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing or a slight bruise. These soon go away.
Why the test is performed
Gastrin is the main hormone that controls the release of acid in your stomach. When there is food in the stomach, gastrin is released into the blood. As the acid level rises in your stomach and intestines, your body normally makes less gastrin.
Your doctor may order this test if you have signs or symptoms of a problem linked to an abnormal amount of gastrin. This includes peptic ulcer disease.
Normal values are generally less than 100 pg/mL.Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test result.
What abnormal results mean
Too much gastrin causes severe peptic ulcer disease. A higher than normal level may also be due to:
- Chronic kidney disease
- Long-term gastritis
- Over-activity of the gastrin-producing cells in the stomach (G-cell hyperplasia)
- Helicobacter pylori infection of the stomach
- Use of antacids or medicines to treat heartburn
- Zollinger-Ellison syndrome, a gastrin-producing tumor that may develop in the stomach or pancreas
What the risks are
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Salwen MJ, Siddiqi HA, Gress FG, Bowne WB. Laboratory diagnosis of gastrointestinal and pancreatic disorders. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 22.