### What to Expect from a Gastrin Test and What the Results Mean A gastrin test is a simple blood test that measures the amount of gastrin in your blood. Gastrin is a hormone produced by your stomach to help release gastric acid, which is essential for digesting food and absorbing nutrients, especially proteins and amino acids. Your stomach produces 2 to 3 liters of acidic fluid daily. #### Why You Might Need a Gastrin Test Your doctor may order a gastrin test if they suspect you have abnormal gastrin levels, which can affect digestion. Symptoms that might prompt this test include stomach pain, diarrhea, or recurring peptic ulcers. It’s also used to monitor patients who have had a gastrin-producing tumor removed, to ensure it hasn’t returned. #### Preparing for the Test You’ll need to fast for 12 hours before the test, although you can drink water. Avoid alcohol for at least 24 hours before the test. Inform your doctor about any medications or supplements you’re taking, as some may need to be paused. #### Understanding the Results Normal gastrin levels vary by lab, but generally, high levels may indicate conditions like Zollinger-Ellison syndrome, where tumors called gastrinomas produce excess gastrin. These tumors are usually found in the duodenum or pancreas and can lead to too much acid in the digestive system, causing diarrhea and ulcers. High gastrin levels can also result from anti-acid medications or chronic atrophic gastritis, both of which damage the stomach lining and reduce acid production, causing the stomach’s pH to rise. If you’ve had a gastrinoma removed and your gastrin levels are still high, it could mean the tumor has returned or the surgery wasn’t successful. Low gastrin levels are rare but can lead to poor nutrient absorption and a higher risk of digestive infections. In most cases, normal or low gastrin levels are not a cause for concern.