Reflux with bad breath can be caused by indigestion, Helicobacter pylori infection, gastritis combined with oral diseases. 1. Indigestion: Taking too much greasy food, reducing exercise and other triggers may cause gastrointestinal peristalsis to slow down, and when food stays in the stomach for too long and leads to bacterial imbalance, the symptom of regurgitation with bad breath may occur. 2. Helicobacter pylori infection: when there is gastritis caused by Helicobacter pylori infection, the absorption and peristaltic function of the stomach becomes poor, the symptoms of regurgitation with bad breath may occur. 3. Gastric disease combined with oral disease: gastritis, gastric ulcer and other gastric diseases may affect the digestive function of the symptoms of regurgitation; dental caries, oral ulcers and other oral diseases may lead to bacterial growth and bad breath symptoms. When both diseases are present at the same time, symptoms of regurgitation with bad breath may occur. Reflux with bad breath can also be caused by other reasons, so it is necessary to further check gastroscopy, Helicobacter pylori breath test, X-ray and other items to find the cause.