What is gastritis?

Gastritis describes a group of conditions characterised by inflammation of the stomach lining. Almost everyone will experience gastritis at some point, but it is not usually dangerous and generally improves with treatment. It can occur suddenly, or it may develop slowly over time.

Symptoms of gastritis include reduced hunger, stomach-ache or nausea and vomiting. In some cases, it can also lead to ulcers, bleeding in the stomach or an increased risk of stomach cancer. Quite often though, gastritis produces no noticeable symptoms.

Upset stomach, stomach pain, causes of stomach pain, causes of indigestion.

An inflammation of the stomach lining as a result of gastritis.


The stomach lining is a wrinkled layer within the stomach that releases mucus and other substances that help to break down food. This mucus creates a protective barrier between the stomach wall and acids inside the stomach. Gastritis occurs when a hole in the mucus barrier develops, allowing highly acidic digestive juices to pass through and damage the stomach wall. The end result is inflammation that may occur suddenly, or gradually over time.

Biology of gastritis, stomach lining and gastritis, changes to stomach lining, formation of stomach ulcers.

The formation of an ulcer due to inflammation caused by gastritis.

This process can be triggered by a number of different factors, including:

Helicobacter pylori infection

Gastritis is often caused by a bacteria called Helicobacter pylori, or H. pylori for short. More than 30% of the world’s population is infected with H. pylori, making it one of the most common bacterial infections. These bacteria live deep in the mucus that coats the stomach lining.

Although long-term infection is known to cause gastritis in some people, it is also possible for others to carry H. pylori without ever developing symptoms. For this reason, other factors are also thought to play a role in making certain people more sensitive to H. pylorirelated gastritis.


A class of medications, known as non-steroidal anti-inflammatory drugs (NSAIDs), may cause gastritis when taken regularly. Common NSAIDs include aspirin, ibuprofen and naproxen. These medications decrease the levels of certain prostaglandins in the body, which help to protect the stomach lining from stomach acid.

Other medications and drugs that can cause gastritis include corticosteroids, cocaine, alcohol and chemotherapy medications.

Autoimmune response

In rare cases, a condition called autoimmune gastritis may develop, usually in older adults. The term ‘autoimmune’ describes a situation in which the body’s own immune system mistakenly attacks healthy cells, as if fighting an infection or healing a wound. In autoimmune gastritis, this attack causes inflammation and damage to the stomach lining, which may prevent the body from absorbing nutrients, such as vitamin B12. A lack of vitamin B12 can lead to a serious condition, called pernicious anaemia.

Underlying medical condition

Gastritis can be caused by a medical condition called bile reflux. Bile is a fluid produced by the liver to remove toxic substances, break down fat and help with digestion. Usually, bile is stored in the gall bladder and is released into the small intestine after eating. Bile reflux occurs when bile flows back up through the small intestine and leaks into the stomach.

Other conditions that can cause gastritis include severe stress, major surgery or trauma, infection with a virus, fungus or parasite, Crohn’s diseaseHIV/AIDS and kidney disease.

Risk factors

Risk factors that increase the likelihood of developing gastritis include:

  • Age – older adults are more likely to develop gastritis as they have thinner stomach linings and a higher chance of H. pylori infection;
  • Regular use of alcohol and certain medications, such as NSAIDs and corticosteroids, and;
  • High stress from daily life or a traumatic event.


There are four types of gastritis:

  • Acute gastritis – the painful inflammation of the lining of the stomach, which occurs suddenly and usually settles down within a few days;
  • Chronic gastritis – the long-term inflammation of the lining of the stomach, which can last several years;
  • Erosive gastritis – a type of chronic gastritis that wears away the stomach lining over time, which leads to bleeding, thinning of the stomach lining, or ulcers of the stomach or small intestine, and;
  • Autoimmune gastritis – a type of chronic gastritis caused by an autoimmune response.

Signs and symptoms

In many cases, gastritis does not produce any symptoms. When present though, symptoms may include:

  • Reduced hunger;
  • Weight loss;
  • Stomach-ache just under the ribs;
  • Nausea and vomiting;
  • Hiccups, and;
  • Heartburn.

Less commonly, the stomach lining can wear away over time, leading to stomach ulcers and bleeding. When this occurs, symptoms may also include very dark stools, or blood in the stool or vomit.

Methods for diagnosis

Your doctor will usually suspect gastritis based upon your symptoms. Tests are usually performed to help find the underlying cause. These include:

H. pylori testing

A blood or stool test may be requested to help identify H. pylori bacteria. Sometimes a breath test may also be used to check for H. pylori bacteria.

Upper endoscopy

If further testing is required, your doctor may refer you to have an upper endoscopy (gastroscopy). During an upper endoscopy, you will be sedated and a long, narrow telescopic camera will be inserted into your throat to view the upper digestive system, including the lining of the stomach. Tissue samples (biopsy) can be obtained from the lining of the stomach, especially if there are any suspicious lesions.

Endoscopic diagnosis of gastritis in the stomach.

An endoscopy procedure.

Tissue biopsy

Analysis of a biopsy taken during an upper endoscopy, under a microscope by the pathologist, can help confirm gastritis. It can also help to assess the severity of gastritis and identify the underlying cause, such as the presence of H. pylori bacteria or autoimmune gastritis.

Types of treatment

The main treatments for gastritis are aimed at avoiding substances that trigger inflammation, reducing the amount of acid in the stomach and fighting H. pylori infection (if present). Your doctor may recommend one or more of the following options:

Self care

Your doctor may recommend lifestyle changes to improve your overall digestive health. For example, changes to your eating habits could include limiting portion sizes, keeping regular meal times and eating a balanced diet, free of foods that cause irritation. Cutting down smoking and alcohol, and avoiding NSAIDs use may also improve symptoms. It is also recommended to limit caffeinated drinks, such as coffee, tea and soft drinks, which can increase stomach acid secretion.

Similarly, moderate exercise has been shown to improve digestion by encouraging faster movement of food through the digestive system. As stress can cause increased production of stomach acid and slow digestion, relaxing activities such as yoga, tai chi or massage may also be recommended.



For mild cases of gastritis, over-the-counter antacid tablets may be suggested to balance the level of acid in the stomach. Common antacids include aluminium hydroxide, magnesium carbonate and magnesium triscilicate. Antacids may also contain an ingredient, called simeticone, to help reduce wind.

Histamine blockers

If antacids are not effective, your doctor may prescribe a stronger family of medications, known as histamine 2 (H2) blockers. These medications reduce the amount of acid in the stomach by blocking a natural chemical in the body, called histamine. Some examples of H2 blockers for gastritis include ranitidine, cimetidine, and famotidine.

Proton pump inhibitors

Proton pump inhibitors (PPIs) are a family of medications that also reduce the amount of stomach acid, but in a different way. The main PPIs prescribed for gastritis are esomeprazole, pantoprazole and omeprazole tablets.


In cases of gastritis caused by H. pylori, your doctor will most likely prescribe antibiotics to kill the bacteria. Most commonly, the antibiotics amoxicillin and clarithromycin are prescribed together with esomeprazole or omeprazole. This combination treatment is referred to as PPI-based triple therapy.

If triple therapy does not clear the infection, your doctor may try a different combination or dosage of medications. Side effects of treatments for H. pylori infection may include nausea, heartburn, headache and diarrhoea.

Potential complications

If left untreated, gastritis can lead to stomach ulcers (known as peptic ulcer disease). In cases of long-term H. pylori infection or autoimmune gastritis, a condition called atrophic gastritis can occur.

Atrophic gastritis

Atrophic gastritis involves destruction of the cells in the stomach lining that produce the digestive juices. These changes to the stomach lining are linked to an increased risk of stomach cancers.


Gastritis can also spread to involve the first part of the small intestine (duodenum), known as duodenitis. It is managed in the same way as gastritis.

Peptic ulcer disease

Peptic ulcer disease, also known as stomach ulcers, occurs when the lining of the stomach or duodenum erodes away, exposing the underlying delicate tissues, which are highly sensitive to damage from stomach acid. It is a long-term complication of gastritis and duodenitis.

Without treatment, peptic ulcer disease can lead to bleeding from the stomach, which can be severe and life-threatening. Occasionally, the ulcer can progress through the entire stomach or duodenal wall, causing a perforation. This can allow stomach contents and acid to contaminate the abdominal cavity, which is a serious medical condition that needs immediate treatment.


Gastritis usually is not serious and improves quickly with lifestyle changes and medications. In fact, it is quite common for mild gastritis to pass without treatment or a visit to the doctor.

However, if your gastritis is caused by H. pylori infection, your doctor will most likely schedule a follow-up appointment after treatment has finished to check that the infection has cleared. This is because long-term infection can lead to ulcers, in some cases.


Methods for preventing gastritis closely mirror the self-care treatment options. For example, modifying your lifestyle to include healthy eating, moderate exercise and activities to reduce stress may be recommended by your doctor. Similarly, cutting down your intake of alcohol and NSAIDs may also help to prevent irritation of the stomach lining.

At present, it is unknown exactly how H. pylori bacteria is spread. However, it is thought to be passed from person to person through crowded living conditions and poor sanitation. For this reason, the risk of developing gastritis may be reduced through good hygiene measures.

Last Reviewed: 03/10/2018