Medical Author: Melissa Conrad Stöppler, MD
Helicobacter pylori (H. pylori) infects the cells of the stomach lining, causing production of a toxin and subsequent inflammation that can lead to a variety of symptoms and signs. The clinical picture is very variable in that some people who are infected do not have any symptoms. Others may have mild symptoms, while others develop severe symptoms and ulcers.
Mild symptoms of H. pylori infection are
In more severe cases, those affected by H. pylori may experience
- vomiting blood,
- dark stool (from bleeding into the gastrointestinal tract),
- anemia (from red blood cell loss due to bleeding),
- bad breath,
- worsening abdominal pain.
Causes of Helicobacter pylori (H. pylori) infection
H. pylori is a type of bacteria that can invade the lining of the stomach, causing an infection. The inflammation results from production of a toxin known as vacuolating cytotoxin A (Vac-A). The inflammation can lead to ulcer formation.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Main Article on Helicobacter pylori (H. pylori) Symptoms and Signs
Pictures, Images, Illustrations & Quizzes
16 Foods That Boost and Improve Your Immune SystemFight cold and flu with foods that boost and improve your immune system. Reach for bright-colored antioxidant and vitamin-rich...learn more »
Digestive Disorders: Common MisconceptionsLearn about the digestive system and common misconceptions of digestive disorders. Read about what causes ulcers, heartburn,...learn more »
Is It Contagious? What Diseases Are Contagious?Is it contagious? Take this quiz to learn about contagious diseases, how contagious diseases are spread, and myths and facts...learn more »
Stomach Pain Quiz: Nausea & Other CausesTummy Troubles? Get a better idea of what's causing the nausea, vomiting, bloating, gas, constipation, diarrhea, pain, and other...learn more »
Other Causes of Helicobacter pylori (H. pylori) Symptoms and Signs
Examples of Medications for Helicobacter pylori (H. pylori) Symptoms and Signs
- amoxicillin (Amoxil, Moxatag, Larotid)
- bismuth subsalicylate (Pepto Bismol, Kaopectate, Bismatrol Maximum Strength, and others)
- clarithromycin, Biaxin
- esomeprazole (Nexium, Nexium 24HR, Nexium IV)
- metronidazole (Flagyl, Flagyl ER) Antibiotic
- omeprazole, omeprazole/sodium bicarbonate, Prilosec, Zegerid, Prilosec OTC, Zegerid OTC
- tetracycline (Sumycin [Discontinued])