Stomach acid can be caused by Helicobacter pylori infection; it can also be caused by other reasons such as diet and medication. 1. Caused by Helicobacter pylori infection: Stomach acid is a part of gastric juice, and its main component is hydrochloric acid. The right amount of stomach acid can activate pepsin to ensure normal digestive function. If H. pylori infection occurs, it may lead to gastritis, gastric ulcer and other diseases, and the phenomenon of increased gastric acid secretion. 2. Other causes: Irregular diet, drugs, alcohol, taking spicy and stimulating food, etc., may also lead to increased secretion of stomach acid. So when the phenomenon of stomach acid, you need to further check the gastroscope, breath test and other items to find the cause, and then under the guidance of the doctor treatment.