Gastrin

Does this test have other names?

No.

What is this test?

This test measures the amount of gastrin in your blood. Gastrin is a hormone made by G cells in the lower part of your stomach. It controls the release of gastric acid to help break down food.

Why do I need this test?

You may need this test if your healthcare provider wants to check for high levels of gastrin. This test also helps to diagnose and keep track of different conditions. They include:

• Gastrinomas. Tumors that produce gastrin.

• Zollinger-Ellison (ZE) syndrome. A rare condition with tumors in the small intestine or pancreas.

• G-cell hyperplasia. Cells in the stomach make too much gastrin. 

What other tests might I have along with this test?

You may also have lab tests like a gastric acid level, a pH test to measure the acid in your stomach juices, or other tests that check gastrin production. You may also have imaging tests or an endoscopy. For the endoscopy, the healthcare provider uses a small camera to look in your stomach. 

What do my test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

The results are usually expressed in picograms per milliliter of blood (pg/mL). The normal range is:

• 0 to 180 pg/mL for adults

Your levels may be higher if you are an older adult.

People with ZE syndrome or G-cell hyperplasia usually have levels of gastrin in their blood that are quite high. But you could have ZE syndrome without high levels of blood gastrin. Other conditions and some medicines can also raise gastrin levels.  

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore. 

What might affect my test results?

Things that may affect your test results include:

• Having peptic ulcer surgery

• Eating a lot of high-protein foods

• Taking insulin to treat diabetes

• Taking antacids or other medicines that block gastric acid production

• Taking calcium supplements

• Having drinks, food, or medicine with caffeine

• Taking antidepressants, which can lower your gastrin levels

How do I get ready for this test?

You must not eat or drink for 12 hours before the test. You can drink water. Ask your healthcare provider if there are any medicines that you should stop taking before the test. Don't drink alcohol for at least 24 hours before having this test. Tell your healthcare provider about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.