A duodenal ulcer is an open sore that forms in the lining of the duodenum, the first section of the small intestine just beyond the stomach. It affects roughly 5 to 10 percent of people in Western countries at some point in their lives, with about 0.1 to 0.3 percent of adults developing one in any given year. Unlike stomach (gastric) ulcers, which carry a small risk of being cancerous, duodenal ulcers are almost always benign.
Where Duodenal Ulcers Form
The duodenum is a short, curved tube that receives partially digested food and stomach acid. About 95 percent of duodenal ulcers develop in the duodenal bulb, the very first portion where acidic stomach contents arrive. The remaining 5 percent form slightly farther along, in the upper part of the descending duodenum. Because this area is constantly exposed to acid, even small breakdowns in its protective mucous lining can quickly deepen into a true ulcer.
What Causes Them
Two factors account for the vast majority of duodenal ulcers: a bacterial infection and regular use of common pain relievers.
H. pylori Infection
A stomach bacterium called Helicobacter pylori is found in roughly 90 percent of people with peptic ulcer disease. The bacterium attaches to the cells lining the stomach and duodenum, weakening their natural defenses. It does this partly by depleting glutathione, a molecule cells rely on to protect themselves from damage. H. pylori also disrupts the balance of acid production: it suppresses the cells that slow acid output while stimulating the cells that ramp it up. The result is more acid hitting a less protected lining. Importantly, most people who carry H. pylori never develop an ulcer. Fewer than 15 percent of infected individuals go on to have ulcer disease, which means other factors like genetics, stress, and lifestyle play a role in who gets sick.
Pain Relievers (NSAIDs)
Nonsteroidal anti-inflammatory drugs, the category that includes ibuprofen, naproxen, and aspirin, are the other major cause. These medications work by blocking enzymes involved in inflammation, but those same enzymes help maintain the protective mucous layer in the gut. Higher doses increase the risk of ulceration by roughly two to three times compared with lower doses. Traditional, nonselective NSAIDs tend to cause ulcers more frequently, though the damage is often milder. Newer, selective versions (like celecoxib) cause fewer ulcers overall but can produce more severe complications when they do occur.
Risk Factors Beyond the Big Two
Smoking is one of the clearest lifestyle risk factors. Smokers have about a 45 percent higher odds of developing a duodenal ulcer compared to nonsmokers. Alcohol on its own does not appear to significantly raise duodenal ulcer risk in most studies, but the combination of smoking and drinking together nearly doubles the odds. Other factors that increase vulnerability include older age, a personal or family history of ulcers, and high levels of psychological stress, which can increase acid secretion and slow healing.
How a Duodenal Ulcer Feels
The most common symptom is a burning or gnawing pain in the upper abdomen, typically between the belly button and the breastbone. What distinguishes duodenal ulcer pain from other types of stomach discomfort is its relationship with food and time of day. The pain often strikes when the stomach is empty and may wake you at night. Eating something or taking an antacid usually brings temporary relief, sometimes within minutes, because food buffers the acid hitting the ulcer. This cycle of hunger pain followed by relief after eating is considered a hallmark pattern, though not everyone experiences it so neatly.
Other symptoms include bloating, nausea, a feeling of fullness after small meals, and loss of appetite. Some people have mild, intermittent discomfort for weeks or months before seeking help. Others have no noticeable symptoms at all until a complication develops.
When Ulcers Become Dangerous
Most duodenal ulcers heal without serious problems, but complications can be life-threatening when they occur.
- Bleeding. An ulcer can erode into a blood vessel. Slow bleeding leads to anemia over time, causing fatigue and shortness of breath. Rapid bleeding produces black, tarry stools or vomit that looks like coffee grounds. Severe hemorrhage requires hospitalization and sometimes a blood transfusion.
- Perforation. The ulcer can eat entirely through the duodenal wall, creating a hole that allows intestinal contents to leak into the abdominal cavity. This causes sudden, severe abdominal pain and is a surgical emergency due to the risk of widespread infection (peritonitis).
- Blockage. Repeated ulceration and scarring can narrow the passage out of the stomach, making it difficult for food to move through. Signs include feeling full quickly, vomiting undigested food, and unexplained weight loss.
How Duodenal Ulcers Are Diagnosed
If your symptoms suggest an ulcer, the first step is usually testing for H. pylori. A urea breath test is the most accurate noninvasive option, with a sensitivity of 97 percent and a specificity of 100 percent. You swallow a small amount of a labeled substance, and if H. pylori is present, it breaks it down in a way that can be detected in your breath. Stool antigen tests are another option, with sensitivity around 92 percent and specificity around 94 percent for the best versions.
An upper endoscopy, where a thin camera is passed down the throat into the duodenum, provides direct visual confirmation of the ulcer. It also allows a doctor to take tissue samples and check for H. pylori at the same time. Endoscopy is especially important when symptoms are severe, when there are signs of bleeding, or when initial treatment hasn’t worked.
Treatment and Healing
Duodenal ulcers typically take about six weeks to heal. Treatment depends on the underlying cause.
Reducing Acid
Proton pump inhibitors (PPIs) are the standard treatment for lowering stomach acid and allowing the ulcer to heal. For an uncomplicated duodenal ulcer, the typical course is once daily for four weeks. Some people need an additional four to eight weeks if healing is incomplete. You can usually tell treatment is working because pain decreases within the first few days to a week.
Eliminating H. pylori
If testing confirms H. pylori, killing the bacteria is essential. Without antibiotics, an ulcer may temporarily heal but will commonly return. The current recommended first-line treatment is a 14-day course of bismuth-based quadruple therapy, which combines an acid reducer with bismuth and two antibiotics. Older regimens based on clarithromycin are no longer recommended as a first choice unless the specific bacterial strain has been tested and shown to be sensitive to it, because resistance rates have climbed too high in many regions.
Completing the full 14-day course matters. Stopping early increases the chance the bacteria survive, which means the ulcer is likely to come back.
Stopping NSAIDs
If an NSAID caused the ulcer, discontinuing the medication (or switching to an alternative that’s gentler on the gut) is the most important step. When NSAIDs can’t be stopped for medical reasons, taking a PPI alongside them helps protect the lining.
What Recovery Looks Like
Most people notice significant pain relief within one to two weeks of starting treatment. Full mucosal healing, confirmed by follow-up endoscopy when needed, generally takes the full six weeks. During recovery, avoiding smoking, alcohol, and NSAIDs gives the lining the best chance to repair itself.
Recurrence is the main long-term concern. An ulcer caused by H. pylori that is treated only with acid reducers, without antibiotics, will frequently come back or a new one will form nearby. After successful eradication of H. pylori, recurrence rates drop dramatically. For NSAID-related ulcers, the risk stays elevated as long as the medications continue.