Digestive Disorders Health Center

How It Feels

The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.

Risks

There is very little chance of a problem from having blood sample taken from a vein.

• You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
• In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
• Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.

Results

A gastrin test measures the level of the hormone gastrin in the blood. Results are usually available in 1 to 2 days.

Normal

The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what?s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.

Normal values may be higher in very young children and older adults.

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Many conditions can change gastrin levels. Your doctor will talk with you about any abnormal results that may be related to your symptoms and past health.

High levels

High gastrin levels may be caused by:

• Zollinger-Ellison syndrome, a rare disease that can cause gastrin levels to increase as high as 450,000 pg/mL.
• Pernicious anemia and conditions in which the stomach is unable to produce gastric acid, such as atrophic gastritis.
• Kidney failure.
• Diseases such as G-cell hyperplasia, peptic ulcers, hypercalcemia, hyperparathyroidism, sarcoidosis, and stomach cancer.
• Surgery to remove a large portion of the intestines (small bowel resection).

Low levels

Low gastrin levels may be caused by hypothyroidism.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• Eating before the test.
• Drinking caffeinated beverages or alcohol right before the test.
• Taking some medicines. Examples of medicines that can affect results include medicines that reduce stomach acid (such as Pepcid, Zantac, or Prilosec) and medicines or supplements that contain calcium (such as Tums or a daily vitamin). Make sure your doctor knows about all the medicines, herbs, and supplements you take.
• Having had stomach ulcer surgery or a small bowel resection. Increased gastrin levels also occur in medical conditions such as kidney failure, rheumatoid arthritis, and cirrhosis.