What Is a Stomach Ulcer (Peptic Ulcer)?

It often starts as a burning ache high in the belly that eases with food, then creeps back a few hours later. A stomach ulcer — doctors call the wider family peptic ulcers — is an open sore in the lining of the stomach or the first part of the small intestine. The short video above puts it plainly: these are open sores that develop on the inside lining, and stomach pain is the most common symptom. Rather than guessing at that pain, it helps to walk through how an ulcer forms, step by step.

Step one: the stomach's protective lining weakens

Your stomach makes strong acid to digest food, and it normally protects itself with a mucus barrier. An ulcer begins when that barrier is worn down and acid starts to damage the lining underneath. Two causes account for most cases: infection with a common stomach bacterium, Helicobacter pylori, and regular use of anti-inflammatory painkillers, which can reduce the lining's defences. Stress and spicy food get blamed a lot, but on their own they are not considered the root cause — though they can certainly make an existing ulcer feel worse. If your main symptom is burning rising into the chest rather than an ache in the belly, our guide to acid reflux (GERD) explains that related but different problem.

Step two: the sore produces its pattern of pain

Once the lining is breached, acid touching the raw area produces the classic burning or gnawing pain between meals or at night. People also describe fullness, bloating, belching, nausea, and finding fatty foods harder to tolerate. Ulcers in the stomach itself are called gastric ulcers; those just beyond it, in the duodenum, are duodenal ulcers — together they are the peptic ulcers. The site's overview video, "Peptic Ulcer", walks through that picture in just over two minutes if you want a second view before an appointment. Some ulcers, it's worth knowing, cause no pain at all and are only found when a complication appears.

Step three: diagnosis looks for the sore — and its cause

Because several conditions can mimic ulcer pain, diagnosis usually means looking directly. The most common route is an upper endoscopy, where a thin camera is passed to view the stomach lining — the procedure itself is explained in our guide to what an endoscopy is and what it shows. Testing for H. pylori, by breath, stool, or a small sample taken during endoscopy, is the other key step, because finding the bacterium changes the treatment plan.

Step four: treatment helps the lining heal

Care generally combines reducing acid so the sore can heal, treating H. pylori infection if it is present, and reviewing any painkillers that may be undermining the lining. Most uncomplicated ulcers heal over a course of treatment, and follow-up sometimes includes a check that the infection has cleared. Warning signs need prompt care rather than a wait-and-see approach: vomiting blood, black stools, sudden severe abdominal pain, faintness, or weight loss you can't explain. Those can signal bleeding or another complication, and they should never be sat on at home.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician and researcher.

Frequently Asked Questions

What is the difference between a gastric ulcer and a duodenal ulcer?
Location. A gastric ulcer sits in the stomach lining itself, while a duodenal ulcer sits in the first part of the small intestine, just beyond the stomach. Both are peptic ulcers, they share the same main causes, and they are investigated and treated in broadly the same way.

Can a stomach ulcer heal on its own?
Small areas of irritation sometimes settle, but a true ulcer usually needs treatment — particularly if H. pylori is involved, because the infection remains and the ulcer can return. Getting checked also rules out other causes of the same pain, so self-treating for months is not a good plan.

Does spicy food cause ulcers?
No. Spicy food can aggravate pain from an existing ulcer, which is why the link is so often assumed, but it does not create the sore. The well-established causes are H. pylori infection and regular use of anti-inflammatory painkillers weakening the stomach's protective lining.

How long does an ulcer take to heal?
Healing takes a course of treatment rather than a day or two, and the exact length depends on the ulcer's size, its cause, and whether the infection has cleared. Your clinician may recheck that H. pylori is gone after treatment, and will tell you if a follow-up look at the stomach is needed.

Educational only — this article is general information about stomach and peptic ulcers, not medical advice and not a diagnosis. Ongoing stomach pain, vomiting blood, black stools, or sudden severe abdominal pain should be discussed promptly — urgently for the warning signs — with your own clinician.