Helicobacter pylori (H. pylori) Infection: Symptoms & Signs

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Medically Reviewed on 1/22/2016

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

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.

Medically Reviewed by a Doctor on 1/22/2016

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