Mild nausea may be caused by early pregnancy reaction, overeating, gastritis, gastric ulcer and other reasons. 1. Early pregnancy reaction: women in the early stages of pregnancy can experience mild nausea and vomiting, which needs to be ruled out by relevant examinations. 2. Overeating: too much food can accumulate in the stomach and not be easily digested, and mild nausea can also occur. 3. Gastritis and gastric ulcer: Nausea and vomiting, stomach pain and bloating may occur when suffering from gastritis and gastric ulcer, which can be relieved by taking omeprazole and bismuth potassium citrate. The above symptoms need to consult a doctor in time, under the guidance of a professional physician to clarify the cause of the disease.