H₂ receptor blockade is to isolate H₂ receptors, inhibit gastric acid secretion, inhibit pepsin activity, improve gastric mucosal microcirculation, promote cell regeneration, and repair ulcers. H₂ receptor blockers represented by drugs such as cimetidine, ranitidine, famotidine, etc., in the clinic is mainly used in the treatment of gastric ulcers, duodenal ulcers and so on. H₂ receptor blockers, may cause diarrhea, headache, drowsiness, fatigue, myalgia, constipation and other adverse reactions. H₂ receptor blockers have the potential for drug reactions when taken with other medications. It should be used with caution in cases of hepatic and renal insufficiency, is contraindicated in pregnant and lactating women, and is contraindicated in cases of hypersensitivity to certain components of the drug. It is recommended to apply under the supervision of a physician, do not self-medicate.