There are always different patients in the rheumatology outpatient and inpatient departments asking the same question: Doctor, why is there a stomach protector in my prescription? My stomach is fine, and I can eat and drink! In this regard, I am here to give the majority of patients a simple answer to this question. 1, rheumatic diseases: systemic lupus erythematosus, leukodystrophy or other vasculitis and other diseases in the basic treatment will contain a variety of different doses of hormones (prednisone, Medrol or even dexamethasone, etc.), and hormones can cause gastric mucosal lesions, and even lead to gastric ulcers and gastric bleeding; the reasons are as follows: on the one hand, glucocorticoids can stimulate increased secretion of gastric acid and pepsin, so that the gastric damage factors are enhanced. On the other hand, glucocorticoids can weaken the function of prostaglandins to protect the gastric mucosa, which weakens the protective factors of the stomach. Therefore, in order to prevent the damage to the gastrointestinal mucosa caused by hormones, doctors will choose different drugs according to the patient’s age and the amount of hormones and other factors. 2. Another part of the patients may ask: “Doctor, I have ankylosing spondylitis or rheumatoid arthritis, and your prescription does not contain hormonal drugs, so why should I also choose stomach-protective drugs?” Before answering this question, a little knowledge is needed: all kinds of arthritis treatment should include anti-inflammatory and analgesic drugs, which are often called NSAIDs, and patients with arthritis often need to take these drugs for a long time, especially in patients with ankylosing spondylitis; however, these drugs can lead to multi-system weak acid fat-soluble drugs. They can directly cross the gastric mucosal barrier, leading to reverse H+ diffusion and causing mucosal damage; on the other hand, these drugs can inhibit cyclooxygenase activity. This inhibits the synthesis and secretion of endogenous prostaglandins, which weakens the protective mechanism of the mucosa. It has been mentioned in the literature that the mucous membrane of a normal person can lead to ulcers after one week of taking these drugs. Therefore, during the consultation of such patients, doctors also choose different doses and types of drugs for stomach protection, depending on the actual situation.