Gastritis

ByNimish Vakil, MD, University of Wisconsin School of Medicine and Public Health
Reviewed/Revised Mar 2023
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Gastritis is inflammation of the stomach lining.

  • When symptoms of gastritis do occur, they include abdominal pain or discomfort and sometimes nausea or vomiting.

  • Doctors often base the diagnosis on the person's symptoms, but sometimes they need to examine the stomach with a flexible viewing tube (upper endoscopy).

  • Treatment is with medications that reduce stomach acid and sometimes antibiotics.

(See also Introduction to Gastritis and Peptic Ulcer Disease.)

The stomach lining resists irritation and can usually withstand very strong acid. Nevertheless, in gastritis, the stomach lining becomes irritated and inflamed.

Gastritis is divided into two categories based on how severe it is:

  • Erosive

  • Nonerosive

Erosive gastritis is more severe than nonerosive gastritis. This form involves both inflammation and wearing away (erosion) of the stomach lining. Erosive gastritis typically develops suddenly (called acute erosive gastritis) but may develop slowly (called chronic erosive gastritis), usually in people who are otherwise healthy.

Chronic Gastritis
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The red and darker pink patches represent areas of deep, chronic inflammation of the stomach lining.
Photo provided by David M. Martin, MD.

Nonerosive gastritis is characterized by changes in the stomach lining that range from wasting away (atrophy) of the stomach lining to transformation of stomach tissue into another type of intestinal tissue (metaplasia). Often, several types of white blood cells accumulate in the stomach and cause varying degrees of inflammation. Inflammation can occur in the entire stomach or only in certain parts.

Causes of Gastritis

NSAIDs]), alcohol, and disorders of the immune system.

Erosive gastritis is commonly caused by alcohol, stress resulting from severe illness, and irritants such as medications, especially aspirin and other NSAIDs. Less common causes include Crohn disease, radiation, bacterial and viral infections (such as cytomegalovirus), the ingestion of corrosive substances, and direct injuries (such as by the insertion of a nasogastric tube). In some people, even a baby aspirin taken daily can injure the stomach lining.

Nonerosive gastritis is usually caused by Helicobacter pylori infection.

Infectious gastritis not caused by Helicobacter pylori is rare.

Viral gastritis or fungal gastritis may develop in people who have or have had a prolonged illness or an impaired immune system, such as those who have AIDS or cancer or those who take immunosuppressant medications.

Acute stress gastritis, a form of erosive gastritis, is caused by a sudden illness or injury. The injury may not even be to the stomach. For example, extensive skin burns, head injuries, and injuries involving major bleeding are typical causes. Exactly why serious illness can lead to gastritis is not known but may be related to decreased blood flow to the stomach, an increase in the amount of acid in the stomach, and/or to impairment of the stomach lining's ability to protect and renew itself.

Acute Gastritis
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The small, scattered red dots are inflamed areas of the stomach lining caused by infection with Helicobacter pylori.
Photo provided by David M. Martin, MD.

Radiation gastritis can occur if radiation therapy is delivered to the lower left side of the chest or upper abdomen, where it can irritate the stomach lining.

Postgastrectomy gastritis occurs in people who have had part of their stomach surgically removed (a procedure called partial gastrectomy). The inflammation usually occurs where tissue has been sewn back together. Postgastrectomy gastritis is thought to result when surgery impairs blood flow to the stomach lining or exposes the stomach lining to an excessive amount of bile (the greenish yellow digestive fluid produced by the liver).

Atrophic gastritis causes the stomach lining to become very thin (atrophic) and to lose many or all of the cells that produce acid and enzymes. This condition can occur when antibodies attack the stomach lining (termed autoimmune metaplastic atrophic gastritis). Atrophic gastritis can also occur in some people who are chronically infected with H. pylori bacteria. It also tends to occur in people who have had part of their stomach removed.

Eosinophilic gastritis may result from an allergic reaction to an infestation with roundworms, but usually the cause is unknown. In this type of gastritis, eosinophils (a type of white blood cell) accumulate in the stomach wall.

Ménétrier disease, a rare disorder whose cause is unknown, is a type of gastritis in which the stomach wall develops thick, large folds and fluid-filled cysts. The disease may be due to an abnormal immune reaction and has also been associated with Helicobacter pylori infection.

Symptoms of Gastritis

Gastritis usually causes no symptoms. When symptoms do occur, they vary depending on the cause and may include pain or discomfort or nausea or vomiting, problems that are often simply referred to as indigestion (dyspepsia).

Nausea and intermittent vomiting can result from more severe forms of gastritis such as erosive gastritis and radiation gastritis.

Indigestion can occur, especially with erosive gastritis, radiation gastritis, postgastrectomy gastritis, and atrophic gastritis. Very mild indigestion also occurs with acute stress gastritis.

Complications of gastritis

Complications of gastritis include

  • Bleeding

  • Ulcers

  • Narrowing of the passage out of the stomach

Acute stress gastritis may lead to bleeding within a few days after an illness or injury, whereas bleeding tends to develop more slowly in the case of chronic erosive gastritis or radiation gastritis. If bleeding is mild and slow, people may have no symptoms or may notice only black stool (melena), caused by the black color of digested blood. If bleeding is more rapid, people may vomit blood or pass blood in their stool. Persistent bleeding can lead to symptoms of anemia, including fatigue, weakness, and light-headedness.

Gastritis can lead to stomach ulcers (gastric ulcers), which may cause the symptoms to get worse. If an ulcer goes through (perforates) the stomach wall, stomach contents may spill into the abdominal cavity, resulting in inflammation and usually infection of the lining of the abdominal cavity (peritonitis) and serious illness, with sudden worsening of pain.

Some complications of gastritis are slow to develop. The scarring and narrowing of the stomach outlet that can result from gastritis, especially from radiation gastritis and eosinophilic gastritis, can cause severe nausea and frequent vomiting.

In Ménétrier disease, fluid retention and swelling of the tissues (edema) may occur because of loss of protein from the inflamed stomach lining.

Postgastrectomy gastritis and atrophic gastritis may cause symptoms of anemia, such as fatigue and weakness, because of decreased production of intrinsic factor (a protein that binds vitamin B12, allowing the B12 to be absorbed and used in the production of red blood cells).

In a small percentage of people with atrophic gastritis, the stomach tissue transforms into another type of digestive tract tissue (metaplasia). In an even smaller percentage of people, metaplasia leads to stomach cancer.

Diagnosis of Gastritis

  • Upper endoscopy

A doctor suspects gastritis when a person has upper abdominal discomfort, pain, or nausea. Tests usually are not needed. However, if the doctor is uncertain of the diagnosis, or if symptoms do not resolve with treatment, the doctor may do upper endoscopy.

During upper endoscopy, a doctor uses an endoscope (a flexible viewing tube) to examine the stomach and some of the small intestine. If necessary, the doctor can do a biopsy (removal of a tissue sample for examination under a microscope) of the stomach lining.

Treatment of Gastritis

  • Medications that reduce acid production and antacids

  • Sometimes antibiotics that treat H. pylori infection

  • Treatments to stop bleeding

Regardless of the cause of gastritis, symptoms of gastritis can be relieved by taking medications that neutralize or reduce the production of stomach acid and by discontinuing medications that cause symptoms. (See also Medications for the Treatment of Stomach Acid.)

Medications for gastritis

For mild symptoms, taking antacids, which neutralize acid that has already been produced and released in the stomach, is often sufficient. Almost all antacids can be purchased without a doctor's prescription and are available as tablets, soft chews, or liquids.

Acid-reducing medications include

H2 blockers are usually more effective than antacids in relieving symptoms, and many people find them far more convenient. Doctors most often prescribe proton pump inhibitors for gastritis associated with bleeding. People typically need to take these acid-reducing medications for 8 to 12 weeks.

Doctors may prescribe , which helps coat and heal the stomach and also prevents irritation.

When gastritis is caused by H. pylori infection, antibiotics are also prescribed.

Erosive gastritis

People with erosive gastritis must avoid taking medications that irritate the stomach lining (such as NSAIDs). Proton pump inhibitors or H2 blockers are prescribed to help protect the stomach lining.

Acute stress gastritis

Most people with acute stress gastritis recover fully when the underlying illness, injury, or bleeding is controlled. However, a small percentage of people in intensive care units have heavy bleeding resulting from acute stress gastritis, which can be fatal. Therefore, doctors try to prevent acute stress gastritis after a major illness, major injury, or severe burn. Medications that reduce acid production are commonly given after surgery and to people in intensive care units to prevent acute stress gastritis. These medications are also used to treat any ulcers that form.

For people with heavy bleeding resulting from acute stress gastritis, a wide variety of treatments have been used. Few of these treatments, however, improve the outcome. Bleeding points can be temporarily heat-sealed (cauterized) during an endoscopy, but bleeding may start again if the underlying illness persists. If bleeding continues, part of the stomach may have to be removed as a lifesaving measure, but this is rarely needed.

Other types of gastritis

There is no cure for postgastrectomy gastritis or atrophic gastritis. People with anemia resulting from decreased absorption of vitamin B12 that occurs with atrophic gastritis must take supplemental injections of the vitamin for the rest of their lives.

Corticosteroids or surgery may be needed to relieve a blocked stomach outlet caused by eosinophilic gastritis.

Removing part or all of the stomach may cure Ménétrier disease. There are no effective medications for Ménétrier disease.

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