Stomach Ulcer vs Acid Reflux: How to Tell the Difference

The Quick Answer

Acid reflux is stomach acid escaping upward into the esophagus, felt as heartburn rising into the chest. A stomach ulcer is an open sore in the lining of the stomach or upper small intestine, felt as a gnawing or burning pain in the upper belly. Reflux tends to rise, an ulcer tends to stay put.

Acid Reflux in Brief

With acid reflux and GERD, the burning starts below the breastbone and moves up toward the throat, often after meals, when bending over, or lying down. It may come with a sour taste, regurgitation, or a chronic cough. It usually eases with antacids.

Stomach Ulcers in Brief

A peptic ulcer causes a gnawing or burning pain centered in the upper stomach. A telling feature is its timing: ulcer pain often appears when the stomach is empty, such as between meals or at night, and may briefly ease after eating or taking an antacid, then return. Most ulcers are caused by H. pylori bacteria or regular NSAID pain reliever use.

How to Tell Them Apart

• Location: reflux burns upward into the chest and throat, an ulcer stays in the upper belly.
• Timing with food: reflux is often worse after eating and when lying down, ulcer pain is often worse on an empty stomach.
• Warning signs: ulcers can bleed, causing black or tarry stools or vomiting that looks like coffee grounds. Reflux does not do this.

Because they can overlap, and can even occur together, testing is the reliable way to know.

Why the Difference Matters

Acid reflux is managed mainly with diet, lifestyle, and acid-reducing medication. An ulcer needs those acid reducers too, but also treatment of the underlying cause, such as antibiotics for H. pylori or stopping NSAIDs, so the sore can heal. Missing an ulcer risks a complication like bleeding, which is why it is worth pinning down.

How They Are Diagnosed

An upper endoscopy is the best test to tell them apart. It lets me look directly at the esophagus and stomach, confirm or rule out an ulcer, and test for H. pylori. For clear-cut reflux in younger people, treatment may be started without a scope.

When to See a Doctor

See a gastroenterologist if burning upper belly or chest pain is frequent or does not settle with over-the-counter treatment. Seek care promptly for black or bloody stools, vomiting blood, trouble swallowing, or unexplained weight loss, which point to an ulcer or another problem that needs attention.