H. pylori is a bacterium that lives in the protective mucus lining of the stomach. It survives the stomach’s acidic environment by producing an enzyme called urease, which helps neutralize stomach acid around the bacteria.

Over time, the infection may damage the stomach lining, leading to inflammation and increasing the risk of ulcers.

Most people become infected during childhood, often through contaminated food, water, or close person-to-person contact.

1. Burning or Gnawing Stomach Pain

The most common symptom is a burning or aching pain in the upper abdomen.

The pain may: