Stomach discomfort before quitting smoking and stomach discomfort after quitting smoking may be due to the patient’s own gastric diseases that are not related to smoking; it may also be due to gastric diseases caused by smoking, but after quitting smoking and not properly treated. 1. The patient’s own stomach disease: If the patient himself suffers from gastritis, gastric ulcer and other diseases, then regardless of whether to quit smoking, may have stomach discomfort, need to go to the hospital in time for examination. Although the patient’s own stomach disease is not related to smoking, he should quit smoking as early as possible, as the risk of stomach cancer in smokers is 1.5~3 times higher than that in non-smokers. 2. Gastric diseases caused by smoking: nicotine in tobacco not only affects the blood circulation of gastric mucosa, but also leads to the dysfunction of pyloric sphincter, causing bile reflux and other digestive disorders, which in the long run may damage the gastric mucosa, leading to the emergence of chronic gastritis and gastric ulcers, etc. After quitting smoking, patients often need to receive regular medical treatment. After quitting smoking, it is often necessary to receive formal treatment before the upset stomach improves. Patients with upset stomach are advised to quit smoking as soon as possible and go to the hospital for treatment under the guidance of a doctor.