A burning sensation in your stomach is almost always caused by something irritating or weakening the protective lining that shields your stomach wall from its own acid. Your stomach produces hydrochloric acid to digest food, and a thin layer of mucus keeps that acid from damaging the tissue underneath. When that barrier breaks down, or when acid ends up somewhere it shouldn’t be, the result is that familiar burning feeling. The most common culprits are acid reflux, inflammation of the stomach lining (gastritis), certain medications, bacterial infections, and stress-related digestive changes.
Acid Reflux and GERD
Acid reflux is one of the most frequent causes of burning in the upper stomach and lower chest. It happens when the muscular valve at the top of your stomach, which normally opens only to let food in, becomes weak or relaxes at the wrong time. When it does, stomach acid flows back up into the esophagus, which has no protective mucus layer and is highly sensitive to acid. The burning can feel like it starts in your stomach and rises into your chest or throat.
Several factors make this valve more likely to malfunction. Being overweight or pregnant increases pressure on the stomach, pushing acid upward. Smoking weakens the valve directly. A hiatal hernia, where the upper part of the stomach pushes through the diaphragm into the chest cavity, also increases the risk. Certain medications can contribute too, including sedatives, blood pressure drugs called calcium channel blockers, some asthma medications, and tricyclic antidepressants. When reflux happens frequently (more than twice a week for several weeks), it’s generally classified as GERD, a chronic condition that can damage the esophagus over time.
Gastritis: Inflammation of the Stomach Lining
Gastritis refers to inflammation of the stomach’s inner lining and is a direct cause of burning stomach pain. It comes in two main forms. Erosive gastritis physically wears away the lining, creating shallow breaks called erosions that can develop into ulcers. In its acute form, erosions and even bleeding can develop quickly. Non-erosive gastritis involves inflammation without visible damage to the surface, but it still produces burning, nausea, and discomfort.
The causes of gastritis overlap with many items on this list: bacterial infection, heavy alcohol use, long-term painkiller use, and autoimmune conditions where the body’s immune system attacks stomach cells. Autoimmune gastritis tends to be chronic and non-erosive, meaning it causes persistent low-grade inflammation rather than sudden, severe symptoms.
H. Pylori Infection
A spiral-shaped bacterium called H. pylori is one of the most common causes of chronic stomach burning worldwide. Roughly 44% of adults globally carry this infection, though many never develop symptoms. The bacteria survive in the stomach’s harsh acid environment by producing enzymes that neutralize the acid around them, then burrowing into the stomach lining. Once embedded, they trigger chronic inflammation and irritation that weakens the mucus barrier over time.
Left untreated, H. pylori can cause gastritis, peptic ulcers, and in rare cases, stomach cancer. The infection spreads through contaminated food, water, or close contact with an infected person, and it’s easily detected through breath tests, stool tests, or biopsies taken during an endoscopy. Treatment typically involves a combination of antibiotics and acid-reducing medication taken over one to two weeks.
Pain Relievers and Other Medications
Over-the-counter pain relievers like ibuprofen, aspirin, and naproxen (collectively called NSAIDs) are a major cause of stomach burning, especially with regular use. These drugs work by blocking an enzyme called COX-1, which has an important side job beyond managing pain: it helps produce the protective compounds that maintain your stomach’s mucus barrier, blood flow to the lining, and cell repair. When NSAIDs shut down that enzyme, mucus production drops, blood flow to the stomach wall decreases, and damaged cells aren’t replaced as quickly.
NSAIDs also cause direct chemical damage. Because they’re weak acids, they can pass through the mucus layer and into the cells of the stomach lining, where they release damaging molecules from the inside. This combination of weakened defenses and direct injury is why even a few days of regular NSAID use can produce a noticeable burning sensation, and why long-term use significantly raises the risk of erosions, ulcers, and gastrointestinal bleeding.
Food and Drink Triggers
Certain foods and beverages don’t damage the stomach lining permanently but can temporarily increase acid production or irritate tissue that’s already sensitive. Protein-rich meals stimulate the stomach to release more acid through a hormone called gastrin. Spicy foods, citrus, tomatoes, and acidic beverages like coffee and carbonated drinks can aggravate an already inflamed lining. Alcohol is particularly harsh because it acts both as an irritant and, in heavy use, a direct cause of erosive gastritis.
Eating large meals or lying down shortly after eating can worsen symptoms by increasing stomach pressure and making reflux more likely. If you notice a clear pattern between specific foods and your symptoms, those triggers are worth avoiding, but food alone rarely causes stomach burning in someone with a completely healthy lining. Persistent burning after meals often points to an underlying issue like reflux, gastritis, or H. pylori that the food is aggravating rather than causing.
Functional Dyspepsia
Sometimes the stomach burns and no physical cause can be found. When an endoscopy, blood tests, and imaging all come back normal but you still experience recurring upper stomach burning, fullness after meals, or early feelings of being overly full, the condition is called functional dyspepsia. It affects a significant portion of people with chronic digestive complaints.
Functional dyspepsia is thought to involve heightened sensitivity of the stomach’s nerves, abnormal movement of the stomach muscles, or a disconnect between the gut and brain in how pain signals are processed. Stress and anxiety frequently make it worse. It’s a real condition, not imagined, but treatment focuses on managing symptoms rather than fixing a structural problem. Low-dose medications that reduce acid or calm nerve sensitivity, combined with dietary adjustments and stress management, tend to be the most effective approach.
Stress and the Gut-Brain Connection
Psychological stress doesn’t just feel like it affects your stomach. It genuinely does. Stress hormones can increase acid secretion, reduce blood flow to the stomach lining, and slow or speed up digestion in unpredictable ways. Chronic stress is a recognized contributor to both functional dyspepsia and the worsening of existing conditions like gastritis and GERD. People under sustained emotional pressure often report stomach burning even when their diet and medication use haven’t changed.
Warning Signs That Need Prompt Attention
Most stomach burning is uncomfortable but manageable. A few specific symptoms, however, signal something more serious. Vomiting blood or noticing dark, tarry stools suggests bleeding in the digestive tract. Unintended weight loss, persistent loss of appetite, difficulty swallowing, or severe constant abdominal pain can indicate ulcers, strictures, or other conditions that need evaluation. Yellowing of the skin or eyes points to a possible liver or gallbladder issue rather than simple acid irritation.
Burning in the upper stomach area can also occasionally mimic or overlap with heart-related symptoms. If your stomach burning comes with shortness of breath, sweating, or chest pain that spreads to your jaw, neck, or arm, especially during activity or stress, treat it as a possible cardiac event and seek emergency care.