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
There is very little chance of a problem from
having a 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
- 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.
A gastrin test measures the level of the
hormone gastrin in the blood. Results are usually available in 1 to 2
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
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 gastrin levels may be caused
Low gastrin levels may be caused by
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
- Drinking caffeinated beverages or alcohol right before the
- Taking some medicines. Examples of medicines that can affect results include medicines that reduce stomach acid (such as Pepcid, Prilosec, or Zantac) 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