Gastritis Explained: What It Is, What Causes It, and How to Treat It

Los Angeles Times

06-05-2025

When your stomach lining gets irritated, inflamed or damaged, that's gastritis. It's a broad term that covers many conditions, all involving inflammation of the gastric mucosa—the layer inside your stomach. But gastritis isn't a one-size-fits-all diagnosis. It can come on suddenly or creep in over time. It might have noticeable symptoms—or none at all.
While some types clear up quickly, others increase your risk for more serious issues, including gastric cancer. Let's break down what gastritis really is, the different types, why it happens and how it's diagnosed and treated. Table of Contents
Gastritis means inflammation of the stomach lining but the underlying causes, location of the inflammation and tissue damage can vary widely [2], [5]. Some types affect specific areas of the stomach while others are more widespread. The severity and duration also vary: some people get a mild, short-lived episode while others may develop chronic inflammation over years [6]. Gastritis depends on many factors including the underlying cause and severity of the condition.
Non-Atrophic vs. Atrophic Gastritis
Non-atrophic gastritis is usually linked to Helicobacter pylori (H. pylori) infection especially in younger people. It's less structurally damaging to the stomach lining. Helicobacter pylori infection is a common cause of non-atrophic gastritis.
Atrophic gastritis on the other hand involves the loss of gastric glandular cells and is often the result of long-standing H. pylori infection. This type is especially concerning because it's recognized as a major risk factor for gastric cancer [2]. Long-term gastritis can impair the stomach's ability to absorb essential nutrients including folic acid leading to serious health issues such as anemia and other complications.
Acute vs. Chronic Gastritis
Acute gastritis happens suddenly. It can be triggered by alcohol, medications like NSAIDs or stress. Anti-inflammatory medication can also be a trigger and should be stopped if possible. Symptoms usually resolve once the trigger is removed.
happens suddenly. It can be triggered by alcohol, medications like NSAIDs or stress. Anti-inflammatory medication can also be a trigger and should be stopped if possible. Symptoms usually resolve once the trigger is removed. Chronic gastritis develops over time and may be asymptomatic. But left untreated it can lead to more serious complications including ulcers and cancer. Untreated chronic gastritis can also result in a bleeding ulcer which occurs when the stomach lining is severely compromised.
H. pylori is the most common cause of gastritis worldwide. In fact it's found in the majority of patients with stomach inflammation and is particularly prevalent in children [3], [7]. This bacterium disrupts the protective mucus layer in the stomach allowing acid to irritate the tissue. Tests for helicobacter pylori bacteria are essential for confirming the presence of gastritis. Pylori bacteria are found in a significant portion of the population.
Gastritis isn't just about H. pylori. Several other factors can damage the stomach lining: Autoimmune Gastritis – The immune system mistakenly attacks stomach cells, interfering with vitamin B12 absorption and possibly leading to pernicious anemia [5] , [9] .
– The immune system mistakenly attacks stomach cells, interfering with vitamin B12 absorption and possibly leading to pernicious anemia . Acute Erosive Gastritis – Often triggered by severe physical stress, critical illness or direct chemical injury from substances like alcohol or NSAIDs.
– Often triggered by severe physical stress, critical illness or direct chemical injury from substances like alcohol or NSAIDs. Celiac Disease and Food Allergies – Immune responses to gluten or other allergens can also trigger gastric inflammation.
– Immune responses to gluten or other allergens can also trigger gastric inflammation. Crohn's Disease – This inflammatory bowel condition can extend to the stomach.
– This inflammatory bowel condition can extend to the stomach. Iatrogenic Gastritis – Newer cancer therapies have been associated with unique patterns of drug-induced gastritis [4] .
– Newer cancer therapies have been associated with unique patterns of drug-induced gastritis . Major Surgery – Significant physiological stress from major surgery can lead to reduction in blood supply to the digestive system making the stomach lining more susceptible to damage and inflammation.
– Significant physiological stress from major surgery can lead to reduction in blood supply to the digestive system making the stomach lining more susceptible to damage and inflammation. Medical History – Reviewing a patient's medical history is important for diagnosing gastritis as it helps doctors understand the patient's personal and family medical background.
Gastritis symptoms can vary widely from person to person but some common signs include stomach pain, bloating, nausea, vomiting and feeling full after eating. Acute gastritis often presents with severe symptoms such as intense stomach pain and vomiting blood which can be alarming. Chronic gastritis on the other hand may develop gradually and cause milder but persistent discomfort. Symptoms of chronic gastritis can include dull ache in the upper abdomen, feeling full after eating small amounts and ongoing nausea.
In some cases gastritis may not cause any symptoms until significant damage has occurred to the stomach lining. This can allow stomach acids and enzymes to cause further irritation and damage. Consuming too much alcohol or certain foods can exacerbate gastritis pain so it's important to identify and avoid these triggers. If left untreated gastritis can lead to more serious complications such as stomach ulcers, bleeding and scarring of the stomach lining. So if you have persistent or worsening symptoms seek medical attention.
You can't diagnose gastritis based on symptoms alone. Some people don't feel a thing while others may have nausea, bloating or pain. The gold standard for diagnosis is endoscopy where a thin tube with a camera is used to view the stomach lining. Doctors will take biopsies for histological analysis so they can see what's happening at the microscopic level [5].
Blood tests are necessary for confirming diagnoses such as anemia and detecting infections like H. pylori. A stool test is a reliable method to confirm the presence of H. pylori. A breath test can also be used to screen for H. pylori infection. Upper endoscopy is a critical diagnostic procedure for assessing stomach conditions.
Gastritis is often classified using formal systems that help doctors determine severity and risks: Sydney System – Considers the cause, location and appearance of inflammation [6] .
– Considers the cause, location and appearance of inflammation . OLGA Staging – Short for Operative Link on Gastritis Assessment, this system correlates biopsy results with long term cancer risk [2]. These systems help assess changes in the gastric mucosa and guide treatment decisions.
These classifications aren't just academic – they help guide treatment and surveillance.
This type is marked by small bumps or nodules on the stomach lining, typically in the antrum (lower part of the stomach). It's common in younger patients and linked to H. pylori. Symptoms may include epigastric pain, nausea or bloating [1]. Stomach discomfort is also a common symptom, often after eating and may involve nausea and vomiting. Reactive Gastropathy – Caused by bile reflux or NSAIDs.
– Caused by bile reflux or NSAIDs. Lymphocytic Gastritis – Increase in lymphocytes in the stomach lining.
– Increase in lymphocytes in the stomach lining. Eosinophilic Gastritis – High number of eosinophils (a type of white blood cell) and may be related to allergies or autoimmune disease [10]. Inflammatory changes can extend to the small intestine, particularly the duodenum, indicating a broader impact on the digestive system.
Untreated gastritis can cause stomach ulcers, potentially leading to pain and life-threatening bleeding or perforation. Chronic gastritis, especially with H. pylori, elevates stomach cancer risk and can cause digestive disorders [11]. It may also contribute to autoimmune conditions like pernicious anemia and increase the risk of kidney disease. Seek medical help for persistent symptoms. Treatment, including proton pump inhibitors and other medications, depends on the cause and severity, but timely intervention can prevent complications and improve health.
There's no one size fits all treatment. Management depends on the root cause. Anti-nausea medications can be used to alleviate nausea associated with gastritis. The stomach needs to produce acid for digestion but excessive acid can worsen inflammation [8].
H. pylori Eradication
When H. pylori is involved triple therapy—usually a proton pump inhibitor (PPI) plus two antibiotics—is the way to go. This clears the infection and reverses inflammation and reduces long term cancer risk [1]. A breath sample can be used to confirm the presence of H. pylori where the patient swallows a urea substance that the bacteria metabolize and produces carbon dioxide which is detected in the breath sample.
Other Therapies
Autoimmune Gastritis may require vitamin B12 supplementation.
may require vitamin B12 supplementation. Drug-induced Gastritis often improves once the offending medication is stopped.
often improves once the offending medication is stopped. Dietary Support – A growing body of research suggests that certain foods and food-derived compounds may help manage gastritis by soothing the stomach lining and reducing inflammation [12]. These foods can also support the digestive system and overall digestive health.
Gastritis isn't just one disease—it's a spectrum of stomach inflammation with many causes and outcomes. H. pylori is the most common trigger but autoimmune conditions, medications and even food sensitivities can play a role.
With proper diagnosis using endoscopy and biopsy gastritis can often be treated—and in many cases reversed. The key is to get to the root of the inflammation and tailor treatment accordingly.
Understanding the digestive tract and the lining of the stomach is crucial for managing gastritis. As research evolves especially around diet-based interventions the future of gastritis care looks more personalized and promising.
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