Complications:

Most people with severe ulcers experience significant pain and sleeplessness, which can have a dramatic and adverse impact on their quality of life.

Bleeding and hemorrhage

Peptic ulcers caused by H. pylori or NSAIDs can be very serious if they cause hemorrhage or perforate the stomach or duodenum. Up to 15% of people with ulcers experience some degree of bleeding, which can be life-threatening. Ulcers that form where the small intestine joins the stomach can swell and scar, resulting in a narrowing or closing of the intestinal opening. In such cases, the patient will vomit the entire contents of the stomach, and emergency treatment is necessary.

Complications of peptic ulcers cause an estimated 6,500 deaths each year. These figures, however, do not reflect the high number of deaths associated with NSAID use. Ulcers caused by NSAIDs are more likely to bleed than those caused by H. pylori.

Because there are often no GI symptoms from NSAID ulcers until bleeding begins, doctors cannot predict which patients taking these drugs will develop bleeding. The risk for a poor outcome is highest in people who have had long-term bleeding from NSAIDs, blood clotting disorders, low systolic blood pressure, mental instability, or another serious and unstable medical condition. Populations at greatest risk are the elderly and those with other serious conditions, such as heart problems.

Stomach Cancer and Other Conditions Associated with H. pylori

H. pylori is strongly associated with certain cancers. Some studies have also linked it to a number of non-gastrointestinal illnesses, although the evidence is inconsistent.

Stomach Cancers. Stomach cancer, also called gastric cancer, is the second most common type of cancer worldwide. In developing countries where the rate of H. pylori is very high, the risk of stomach cancer is six times higher than in the U.S. Evidence now suggests that H. pylori may be as carcinogenic to the stomach as cigarette smoke is to the lungs.

Eradication of H. pylori may reduce the risk of stomach cancer, but not eliminate it. The patient's risk depends on how much damage the mucus membranes sustained before H. pylori treatment was started. The damage can be measured during an endoscopy.

Infection with H. pylori promotes a precancerous condition called atrophic gastritis. The process most likely starts in childhood. It may lead to cancer through the following steps:

• The stomach becomes chronically inflamed and loses patches of glands that secrete protein and acid. (Acid protects against carcinogens, substances that cause cancerous changes in cells.)
• New cells replace destroyed cells, but the new cells do not produce enough acid to protect against carcinogens.
• Over time, cancer cells may develop and multiply in the stomach.

When H. pylori infection starts in adulthood it poses a lower risk for cancer, because it takes years for atrophic gastritis to develop, and an adult is likely to die of other causes first. Other factors, such as specific strains of H. pylori and diet, might also influence the risk for stomach cancer. For example, a diet high in salt and low in fresh fruits and vegetables has been associated with a greater risk. Some evidence suggests that the H. pylori strain that carries the cytotoxin-associated gene A (CagA) may also be a particular risk factor for precancerous changes.

People with duodenal ulcers caused by H. pylori appear to have a lower risk of stomach cancer, although scientists do not know why. It may be that different H. pylori strains affect the duodenum and the stomach. Or, the high levels of acid found in the duodenum may help prevent the spread of the bacteria to critical areas of the stomach.

Other Diseases. H. pylori has also been weakly associated with other nonintestinal disorders, including migraine headache, Raynaud's disease (which causes cold extremities), and skin disorders such as chronic hives.