Chronic Gastritis: Understanding Your Pathology Report

Section Editor: David Driman MBChB FRCPC
November 13, 2026

Chronic gastritis is long-lasting inflammation of the stomach lining, and it is not cancer. It is one of the most common findings on stomach biopsies, and worldwide, its most common cause is infection with the bacterium Helicobacter pylori.

Chronic gastritis describes what the pathologist sees under the microscope rather than a single disease. Your report will usually add more detail, such as whether the gastritis is active or inactive, how severe it is, and whether H. pylori bacteria were seen. This article explains what chronic gastritis means, what can cause it, and what each part of your pathology report describes.

What does chronic gastritis mean?

Chronic gastritis means there is chronic inflammation in the stomach lining, called the mucosa. Under the microscope, the pathologist sees more immune cells called lymphocytes and plasma cells than are normally present. These cells collect in the lamina propria, the tissue that supports the stomach’s glands, when inflammation has been present for weeks or longer.

Chronic active gastritis and chronic inactive gastritis

Pathologists divide chronic gastritis into two patterns based on whether neutrophils are present. Neutrophils are immune cells that attack the stomach lining when there is ongoing injury, such as an active infection.

Chronic active gastritis. Neutrophils are present along with lymphocytes and plasma cells, which usually indicates current injury, most often an active H. pylori infection. This pattern is explained in more detail in the article on chronic active gastritis.
Chronic inactive gastritis. Neutrophils are not present. This pattern is common after H. pylori has been treated, and mild chronic inactive gastritis often has no specific cause.

The word active does not mean the inflammation is new, and it does not mean the same thing as acute. Both patterns describe long-lasting inflammation, and the only difference is whether neutrophils are present.

What causes chronic gastritis?

Several conditions can cause chronic gastritis. Your doctor will use the other findings in your report and your medical history to work out which one applies to you.

Helicobacter pylori infection. H. pylori is the most common cause of chronic gastritis. The bacteria live on the surface of the stomach lining and cause inflammation that can last for many years if not treated. Pathologists often call this Helicobacter gastritis.
Past Helicobacter pylori infection. After H. pylori is treated, the lymphocytes and plasma cells can remain in the stomach lining for months or even several years.
Autoimmune gastritis. In this condition, the immune system attacks the acid-producing cells in the upper part of the stomach. Over time, it can lead to atrophic gastritis and low vitamin B12 levels.
Medications, alcohol, and bile. Anti-inflammatory medications such as ibuprofen and naproxen, alcohol, and bile that flows back into the stomach more often cause a different pattern of injury called reactive gastropathy. However, they can also be associated with mild chronic inflammation in the stomach lining.
Less common causes. Rarer causes include lymphocytic gastritis, which can be linked to celiac disease, and Crohn disease.

What are the symptoms of chronic gastritis?

Many people with chronic gastritis have no symptoms. When symptoms occur, they can include a burning or aching pain in the upper abdomen, nausea, bloating, and loss of appetite. Some people are found to have chronic gastritis in biopsies taken during an endoscopy done for another reason, such as heartburn or anemia. Chronic active gastritis caused by H. pylori can lead to a gastric ulcer, which may cause pain or bleeding.

How is the diagnosis made?

A pathologist diagnoses chronic gastritis after examining biopsies of the stomach lining under a microscope. The biopsies are usually taken during an upper endoscopy. Ideally, biopsies are taken from both the lower part of the stomach, called the antrum, and the upper part, called the body.

Under the microscope, the pathologist assesses the type and amount of inflammation, whether neutrophils are present, and whether H. pylori can be seen. The pathologist also looks for other changes in the lining, such as atrophy, intestinal metaplasia, and dysplasia.

Severity and activity

Many pathologists describe chronic gastritis using the Updated Sydney System, an international system for describing gastritis. In this system, chronic inflammation and neutrophil activity are each graded as mild, moderate, or severe. Your report may give separate grades for the antrum and the body of the stomach.

Chronic inflammation. This grade describes how many lymphocytes and plasma cells are present. When no cause is found, mild chronic gastritis is often considered a nonspecific finding of little significance.
Activity. This grade describes how many neutrophils are present and how much damage they are causing. In severe activity, neutrophils may fill the glands, forming small collections called pit abscesses. If the surface lining is lost, the pathologist may describe an erosion or an ulcer.

Helicobacter pylori

Your report will say whether Helicobacter pylori bacteria were seen in the biopsies. Pathologists can often see the bacteria on routine slides, but they may use a special stain or immunohistochemistry to look for small numbers of bacteria.

A negative biopsy result does not always mean H. pylori is absent. Proton pump inhibitors, recent antibiotics, and biopsies from only one part of the stomach can all cause the bacteria to be missed. For this reason, your doctor may recommend a breath test or stool test. Learn more about testing for H. pylori.

Other findings in the report

Long-lasting gastritis, especially H. pylori-related gastritis, can change the stomach lining over many years. Your report will usually say whether these changes were seen, because they affect your long-term risk and whether you need follow-up.

Atrophy. Atrophy means some of the stomach’s normal glands have been lost. Learn more about atrophic gastritis.
Intestinal metaplasia. Intestinal metaplasia means the normal stomach lining has been replaced by cells that look like the lining of the intestine. It slightly increases the long-term risk of stomach cancer, as explained in the article on intestinal metaplasia of the stomach.
Dysplasia. Dysplasia is a precancerous change in the lining cells. Most reports will say “negative for dysplasia.” Learn more about gastric dysplasia.

Does chronic gastritis increase my risk of stomach cancer?

Long-term H. pylori infection is the most important cause of stomach cancer worldwide. The risk comes mainly from the gradual development of atrophy and intestinal metaplasia over many years. Treating H. pylori lowers this risk, and chronic gastritis without atrophy, intestinal metaplasia, or dysplasia does not usually need regular follow-up for stomach cancer.

What happens after the diagnosis?

What happens after chronic gastritis is found depends mostly on the cause and on the other findings in your report.

Treating H. pylori. If H. pylori is found, it is treated with a combination of antibiotics and a medication that lowers stomach acid.
Confirming treatment worked. After treatment, your doctor may confirm that the infection is gone with a breath or stool test done at least 4 weeks later. Proton pump inhibitors are usually stopped for at least 2 weeks before the test.
Testing when the biopsy is negative. If the gastritis is moderate or severe but no bacteria were seen, your doctor may still recommend a breath or stool test.
Looking for other causes. Depending on the inflammation pattern, your doctor may check for autoimmune gastritis, review your medications, or test for celiac disease.
Follow-up endoscopy. Most people with chronic gastritis do not need follow-up endoscopies. Follow-up is recommended mainly for people who also have extensive atrophy, intestinal metaplasia with other risk factors, or dysplasia.

Questions to ask your doctor

Is my gastritis active or inactive?
Was the inflammation mild, moderate, or severe?
Were biopsies taken from both the antrum and the body of my stomach?
Was H. pylori seen in my biopsies?
Do I need treatment for H. pylori, and how will we confirm it worked?
Were atrophy, intestinal metaplasia, or dysplasia found?
Could any of my medications be affecting my stomach?
Do I need a follow-up endoscopy?