Peptic ulcer disease mainly refers to gastric ulcers and duodenal ulcers, the onset of which has a close relationship with smoking, in addition to other causes. The incidence of ulcer disease is higher in long-term smokers than in nonsmokers, and the relationship between smoking and gastric ulcers is closer. The ulcer surface of smokers is larger and slower to heal, and even under effective drug therapy, the ulcer heals more slowly than in nonsmokers. This is mainly because: 1, nicotine in tobacco can mildly damage the gastric mucosa, and can exacerbate the damage to the gastric mucosa by ethanol or anti-inflammatory and analgesic drugs, and can also reduce the amount of prostaglandin E in the mucosa and thus lose its protective effect on the mucosa, thus predisposing to ulcer disease. 2, long-term smoking can make the wall cell hyperplasia and gastric alcohol secretion increased, producing self-digestion and ulcers. 3, the nicotine in tobacco can reduce the tension of the pyloric sphincter, so that bile, duodenal fluid easy to reflux in the stomach, and inhibit the pancreatic secretion of bicarbonate, thus weakening the ability to neutralize gastric acid in the duodenal cavity, prone to ulcers in the duodenal bulb.