Many patients go to the pharmacy to buy painkillers because of stomach pain attacks, and after eating for two or three days not only does the stomach pain not improve, but also aggravates the pain, what is going on? In fact, most of the painkillers sold on the market belong to non-steroidal anti-inflammatory drugs, including the familiar aspirin, acetaminophen, indomethacin, diclofenac, ibuprofen, celecoxib, nimesulide, etc. belong to this category of drugs. The mechanism of pain relief and anti-inflammation is mainly through the inhibition of epoxidase, reducing the production of inflammatory mediators prostaglandins, producing anti-inflammatory, analgesic and antipyretic effects. However, this type of painkillers in the anti-inflammatory and pain relief, there is a more obvious side effect is easy to cause damage to the gastric mucosa. And stomach pain is often due to the role of gastric acid erosion of gastric mucosa to produce ulcers and pain, theoretically take painkillers have the role of inhibiting inflammation to relieve pain, in fact, its side effects will lead to gastric mucosal defense and repair capacity, and even exacerbate gastric mucosal damage, so this situation patients need to use acid suppressants rather than painkillers. Like any other drugs, NSAIDs can produce some harmful reactions unrelated to the purpose of medication while exerting therapeutic effects, especially gastrointestinal reactions are the most common, including epigastric discomfort, vague pain, belching, loss of appetite and other various gastrointestinal symptoms. Foreign studies have found that 19% of patients who took traditional NSAIDs developed microscopic gastric ulcers after one week. The correct treatment should be to go to a regular hospital to find out the cause of the stomach pain and to treat it accordingly, rather than blindly taking painkillers. It is important to find out the cause of stomach pain, and if necessary, gastroscopy is needed to make a clear diagnosis. Once the diagnosis of cancer is clear, we can talk about the correct and effective treatment. If we simply take painkillers, it may not only delay the disease, but also aggravate the stomach disease. Is the stomach pain because of gastroduodenal ulcer? Or malignant tumor of stomach? Or functional gastrointestinal disease? There may even be a problem with the pancreas or gallbladder. There are many possible causes behind one and the same symptom. Therefore, when the diagnosis is not clear, do not use painkillers indiscriminately to avoid delaying the condition.