Gastritis occurs when the inner lining of the stomach becomes inflamed, generally when its defenses against acidic digestive juices break down. Gastritis may occur suddenly or gradually. The most common form of gastritis is erosive gastritis, in which acid and/or other factors inflame, damage and wear down the stomach lining.

Gastritis can be caused by a number of factors, including infections, medications and stress. The most common causes are infections with the bacteria Helicobacter pylori (H. pylori) and the use of certain pain relievers called nonsteroidal anti-inflammatory drugs (NSAIDs). Both of these factors may irritate the stomach lining.

The most common symptoms of gastritis are pain or discomfort in the upper abdomen and indigestion. For most patients, symptoms are not severe and gastritis is not a serious condition. However, complications may arise. The most common complications are ulcers. In rare instances, gastritis may lead to cancer of the stomach.

Gastritis is typically diagnosed following a physician’s evaluation of the patient's medical history, a physical examination and a series of diagnostic tests (e.g., endoscopy, blood tests). The biopsy of a tissue sample obtained during endoscopy may provide a definitive diagnosis of gastritis.

For most patients, gastritis improves quickly with treatment. Medications and diet changes are usually all that is required to alleviate the symptoms of gastritis. Medicines that neutralize or block the production of stomach acids and those that protect and heal stomach tissues are the most frequently used. When gastritis is caused by an infection, antibiotics may be used, typically in combination with other medications. Physicians, often gastroenterologists, may recommend a bland diet for patients with gastritis. For some severe and uncommon types of gastritis, part of or all of the stomach may need to be surgically removed.

Gastritis is the inflammation of the inner lining of the stomach (gastric mucosa). The term “gastritis” can refer to several different conditions that cause the stomach lining to become inflamed.

The stomach contains glands that produce such fluids as stomach acid and various enzymes. These gastric juices work together to break down food so it can continue to move through the digestive system. These fluids can be corrosive to the body’s tissues. The stomach contains a multilayered lining designed to contain the fluids and prevent them from reaching delicate tissue. When the defenses of the inner lining break down, these fluids can inflame tissue and cause damage.

Gastritis may be acute or chronic. Acute gastritis develops suddenly and typically demonstrates severe, immediate symptoms. Chronic gastritis tends to develop slowly and often occurs without symptoms. When symptoms do occur, they are frequently mild and only become apparent after the condition has existed for some time.

For many people, gastritis may present few problems or symptoms. In some cases, however, gastritis may create many complications, including:

• Erosions and ulcers. Erosions occur when the surface of the stomach lining is worn away. Peptic ulcers are open sores that are much deeper than erosions. Ulcers typically cause other symptoms, especially pain and bleeding, to get worse. They develop most frequently in erosive gastritis, especially when caused by the bacteria Helicobacter pylori (H. pylori), medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) or acute stress. Ulcers tend to be worse when any of these three potential causes are combined.
  

  

• Scarring and narrowing of the opening to the small intestine (pylorus). In rare cases, gastritis may cause scar tissue to form around the opening to the small intestine. This makes the opening smaller and may cause severe nausea and frequent vomiting due to difficulty in properly passing food out of the stomach. This may be corrected through surgery.
  

  

• Peritonitis. Sometimes, an ulcer may be so deep that it perforates the wall of the stomach. When this happens, the contents of the stomach may spill out into the abdominal cavity, causing peritonitis. This is a severe complication and requires immediate surgery.
  
  
• Metaplasia. Rarely, the cells of the stomach lining change their form. For example, they may begin to resemble intestinal cells. Their ability to properly function is reduced and they may become precancerous.
  
  
• Stomach cancer. In rare instances, gastritis may contribute to cancer of the stomach. This is most common with long-standing Helicobacter pylori infection.

Gastritis refers to many forms of inflammation that affect the stomach in different ways. Gastritis can be classified by its origin, how it occurs or what part of the stomach it affects. Some of these classifications overlap. Some of the most commonly classified types include:

• Erosive gastritis. This is the most common form of gastritis. Acid or other factors can inflame, damage and wear away the inner lining of the stomach (gastric mucosa).  It may be acute or chronic, but is usually chronic.
  
  
• Acute stress gastritis. Results from severe illness or injury. This is most common in patients in intensive care units, especially those with respiratory failure, sepsis (infection in the blood), kidney failure, severe burns, peritonitis or neurologic trauma. It is not known why these problems, which generally do not directly affect the stomach, lead to gastritis. However, the link may be related to decreased blood flow to the stomach or an impairment of the ability of the gastric mucosa to protect and heal itself.
  
  
• Atrophic gastritis. In this chronic form of gastritis, the gastric mucosa becomes very thin (atrophy) and many or all of the cells that produce digestive acids and enzymes are lost. This occurs due to an autoimmune problem in which antibodies attack the body’s own tissues (autoantibodies) or in elderly patients for unknown reasons. It may also be caused by infections or following a partial gastrectomy (surgical removal of part of the stomach).
  
  
• Eosinophilic gastritis and plasma cell gastritis. In these extremely rare types of gastritis, specific types of white blood cells (eosinophils or plasma cells) build up in the wall of the stomach. The cause of this is generally not known, but it could be due to an allergic reaction. These are usually chronic.
  
  
• Ménétrier's disease. In this rare, chronic form of gastritis, giant folds of tissue develop in the stomach wall. These folds may be prone to inflammation or ulcers and generally cause the acid and enzyme-secreting glands in the stomach to waste away, resulting in the loss of certain proteins (e.g., albumin). It most frequently affects men between the ages of 30 and 60. Ménétrier’s disease is also known as giant hypertrophic gastritis or protein losing gastropathy.

The most common cause of gastritis is infection by Helicobacter pylori (H. pylori). These small, curved bacteria may cause acute or chronic gastritis. They typically cause erosive gastritis, but they may be linked to other types as well. Unlike most bacteria, H. pylori are able to survive and even thrive in the highly acidic stomach environment. They grow in the mucous layer that is secreted by the stomach lining (gastric mucosa), which protects them from the digestive juices. The bacteria also produce large amounts of urease, an enzyme that breaks down to form ammonia. Ammonia neutralizes the acidity around the bacteria, further protecting them.

Gastritis that results from an infection of H. pylori may affect the entire stomach or just the lower part, or antrum. Other diseases, including peptic ulcers and stomach cancer, are also linked to chronic H. pylori infections. About two-thirds of the world’s population carries the H. pylori bacteria, according to the U.S. Centers for Disease Control and Prevention (CDC). However, not everyone with the bacteria develops gastritis or the other related conditions. In the United States, the bacteria occur more commonly among adults over age 60. Infection with other forms of bacteria (e.g., Escherichia coli, Salmonella) can also cause gastritis.

Some other potential causes of different types of gastritis include:

• Medications. Many medications may irritate the gastric mucosa and cause erosive gastritis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most likely to cause this irritation, especially with chronic use. These pain relievers tend to cause gastritis in the antrum. The combination of NSAIDs and H. pylori can cause extensive damage to the stomach lining.
  
  
• Injury and stress. Illness, injury or extreme stress may cause erosive gastritis and acute stress gastritis.
  
  
• Disorders of the immune system. Problems with the immune response may cause a patient’s antibodies to attack the lining of the stomach. This generally results in atrophic gastritis.
  
  
• Crohn's disease. This is a type of inflammatory bowel disease. It usually affects the intestines, but in rare cases, it may affect the stomach, causing erosive gastritis.
  
  
• Viruses, fungi and parasites. Viruses, parasites or fungi do not usually infect the stomachs of healthy individuals, but may pose a problem to patients with weakened immune systems, such as those with acquired immune deficiency syndrome (AIDS) or patients taking immunosuppressant medications.
  
  
• Radiation. When radiation is delivered to the upper abdomen or lower chest, it may irritate the lining of the stomach and cause gastritis. Although this does not happen to all patients, physicians may recommend medications to protect the stomach lining before x-rays or radiation treatments of the upper gastrointestinal tract are performed in patients who may be at an increased risk for gastritis.
  
  
• Improper levels of digestive juices or reflux of bile. Too much hydrochloric acid in the stomach may result in erosive gastritis. This may also occur if bile from the small intestine flows back into the stomach.
  
  
• Hypersensitivities or allergies. Patients may be hypersensitive or allergic to foods or other stomach contents (e.g., parasites, infections). Such allergies or sensitivities often cause gastritis.
  
  
• Gastrectomy. Gastritis that occurs following the removal of part of the stomach (partial gastrectomy) is called postgastrectomy gastritis. Inflammation typically occurs where the tissues have been sewn back together and may be due to impaired blood flow or bile back-flow. Inflammation may also occur following a near-total gastrectomy, affecting the small amounts of gastric mucosa that are left.

Certain risk factors increase a person’s likelihood of developing gastritis. Because many gastritis cases are caused by H. pylori bacteria, people who carry the bacteria have an increased risk of developing gastritis. Other risk factors include:

• Substance abuse and certain diets. Excessive alcohol consumption, cigarette smoking or illicit drug use can weaken the stomach lining’s defenses against digestive acids. Diets rich in foods that are spicy, acidic, fried or fatty may also increase the risk of gastritis.
  
  
• Stress. Even minor stresses can increase the production of stomach acids and slow digestion, increasing the risk of gastritis.
  
  
• Race and ethnicity. Gastritis caused by the bacteria H. pylori is most common in the United States in individuals who are black, Native American or Hispanic. Gastritis due to problems with the immune system occurs most frequently in individuals who are black or of Northern European descent.

For most patients, gastritis symptoms are not severe and it is not a serious condition. The most common symptoms are pain or discomfort in the upper abdomen and indigestion. Acute gastritis generally causes sudden symptoms, whereas patients with chronic gastritis often do not exhibit any symptoms.

The pain involved is frequently a gnawing or burning ache, usually located in the upper abdomen. However, it may extend up the chest through the esophagus. The severity of the pain varies widely. Very mild pain or discomfort may occur in acute stress gastritis. Similar or sharper pain occurs most commonly in erosive gastritis, atrophic gastritis and Ménétrier's disease.

indigestion (nonulcer dyspepsia) is another common symptom, but not as common as pain or discomfort. Indigestion is most common in erosive gastritis, atrophic gastritis, plasma cell gastritis and Ménétrier’s disease. Indigestion may encompass several symptoms, including:

• Nausea and vomiting
• Loss of appetite and weight
• Diarrhea
• Belching or bloating
• Feeling of fullness after eating small amounts
• Heartburn
• Hiccups

Gastritis is a major cause of upper gastrointestinal bleeding, though this is rarely serious unless accompanied by ulcers. Bleeding in the stomach may cause hematemesis (vomiting blood) or melena (tarry black stool). It occurs most frequently in erosive gastritis and Ménétrier’s disease. Stress-induced gastritis has a particularly high risk of bleeding, which may be particularly extensive or even life-threatening. Bleeding may begin within just a few days in acute stress gastritis. In other forms, it tends to develop more gradually.

Fluid retention and edema (swelling) may occur due to the loss of proteins from inflamed stomach tissue, especially in Ménétrier’s disease. Anemia (low levels of red blood cells) may also occur. This may be due to bleeding or low levels or absence of vitamin B12, which is important in the production of red blood cells. Deficiency in vitamin B12 due to autoimmune attack (in which antibodies attack the body's own tissues) on the stomach is known as pernicious anemia and may occur as a result of decreased production of a gastric protein that is necessary for B12 absorption. Pernicious anemia is usually associated with atrophic gastritis. Symptoms of both pernicious anemia and anemia due to bleeding include fatigue, weakness and light-headedness.

People experiencing the symptoms of gastritis for more than two or three consecutive days should consult with a physician. Individuals who notice blood in their vomit or stools should contact their physician immediately.

Gastritis is typically diagnosed following a physician’s evaluation of the patient’s medical history, a physical examination and a series of diagnostic tests. However, in some cases, a patient’s symptoms may point so strongly to gastritis that tests are not necessary. A physician, often a gastroenterologist, looks for upper abdominal pain or discomfort and nausea as the primary symptoms of gastritis.

Endoscopy is generally considered the best way to diagnose gastritis. A tiny camera attached to a thin tube is passed through the mouth to look inside the stomach for changes in the stomach lining. Primary signs include edema (swelling), erythema (redness), brittleness, erosions and ulcers.

A sample of tissue from the stomach lining may also be obtained through endoscopy. The biopsy, or laboratory examination, of this tissue sample may provide the definitive diagnosis. It can demonstrate features of acute and chronic inflammation, the presence of infection and the presence of an autoimmune condition (in which antibodies attack the body's own tissues).

In some cases, upper gastrointestinal x-rays of the stomach and small intestine may be used to rule out other possible causes of the symptoms. Liquid barium, a contrast medium that makes the internal organs easier to see on an x-ray, may be used.

For most patients, gastritis improves quickly with treatment. Gastritis caused by medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) typically clears up when the medications are discontinued. Acute stress gastritis generally clears up when the illness, injury or stress that caused it is controlled. Medications and diet changes are usually all that is required for other forms of gastritis.

When gastritis symptoms are mild, antacids may effectively reduce or alleviate symptoms. These over-the-counter medications neutralize the hydrochloric acid in the stomach. They need to be taken several times a day and may cause diarrhea or constipation in some people.

Medications such as H2 blockers may also be used to reduce the production of stomach acid. Proton pump inhibitors block the action of the “pumps” in the cells that secrete acid. They are stronger than H2 blockers. Cytoprotective agents (medications that protect the stomach lining) may also be used to help ease and prevent irritation. Medications in these classes are available in both over-the-counter and prescription forms.

When gastritis is caused by an infection such as Helicobacter pylori, antibiotics are typically used. Two different antibiotics are generally required for one to two weeks. They are usually combined with a proton pump inhibitor and/or a cytoprotective agent. When gastritis is associated with pernicious anemia (low red blood cell count due to vitamin B12 deficiency), the patient may require lifelong supplemental injections of vitamin B12. Antiemetics and fluids may be prescribed if gastritis is accompanied by vomiting.

Physicians typically recommend a bland diet for patients with acute gastritis until the symptoms subside. Foods that cause stomach upset may need to be identified and eliminated from the diet, especially those that are spicy, acidic, fried or fatty. A high protein diet may be recommended for patients with Ménétrier's disease.

Most instances of bleeding in gastritis are minor, disappear on their own and do not require specific treatment. However, heavy, persistent bleeding may be dangerous. Though there are many options to treat this, few are effective in the long term. Blood transfusions may make the bleeding worse. Cauterization (heat-sealing) of bleeding points is possible during endoscopy, but it is often temporary and bleeding may eventually resume.

Gastritis can often be prevented. To help prevent gastritis or minimize attacks, individuals can:

• Adjust their diet and eating habits. Small, frequent meals are easier on the stomach than occasional, large meals. Foods that irritate the lining of the stomach, especially those that are spicy, acidic, fried or fatty, can usually be avoided.
  
  
• Avoid certain substances. Alcohol and cigarette smoking can irritate the stomach and reduce digestion and healing times. Avoiding these substances helps prevent gastritis.
  
  
• Avoid certain medications. Medications that irritate the stomach lining, such as nonsteroidal anti-inflammatory drugs (NSAIDs) can usually be avoided. COX-2 inhibitors are a type of NSAID that are less likely to irritate the stomach. However, they may increase the risk of heart attack and stroke with long-term use. Other pain relievers, such as acetaminophen may be used in place of NSAIDs. People with chronic pain conditions, such as osteoarthritis, should be aware of their medication use and monitor any stomach symptoms.
  
  Patients at high risk for acute stress gastritis (e.g., those in the intensive care unit) may be prescribed medications to reduce the production of stomach acid and protect the lining of the stomach.
  
  
• Manage stress. Stress causes irritation to the stomach. There are a number of stress management and relaxation techniques (e.g., meditation) available to reduce this risk factor and help prevent gastritis.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following gastritis-related questions:

1. Are the symptoms I’m experiencing typical of gastritis?
   
   
2. Which tests will you use to determine if I have gastritis?
   
   
3. Are you certain that I have gastritis?
   
   
4. What may have caused my gastritis?
   
   
5. What treatment options are best for me?
   
   
6. Is there any chance my gastritis will resolve on its own?
   
   
7. Can I treat my gastritis with dietary adjustments alone?
   
   
8. Could my gastritis have been prevented?
   
   
9. How would you recommend that I prevent further gastritis in the future?
   
   
10. Do I also have peptic ulcers, anemia or other complications of gastritis?