Omeprazole side effects and hazards mainly include allergic reactions, gastrointestinal discomfort and concurrent diseases. 1. Allergic reaction: If the patient belongs to the allergic body or is allergic to the product, it may cause the patient to have swelling or red rash on the face, lips, tongue, throat and other parts of the face, as well as symptoms of anaphylactic reaction such as dyspnea, fever, shock, etc., and the patient should consult a doctor immediately. 2. Gastrointestinal discomfort: Omeprazole belongs to the proton pump inhibitors, can inhibit pepsin, lipase, amylase and other digestive enzymes, resulting in slowing down of gastrointestinal peristalsis, which leads to loss of appetite, dyspepsia, poor bowel movement, acid reflux and other gastrointestinal discomfort, in addition, the prolongation of the gastric emptying time increases the chance of bacterial invasion into the body, increasing the incidence of gastrointestinal and systemic infections. 3. Others: Long-term continuous use of omeprazole may result in hepatic and renal impairment, osteoporosis, hypomagnesemia, iron deficiency anemia, neurological/psychiatric disorders. If the patient develops the above symptoms and lesions, it is recommended to stop taking the drug in time and go to a specialized hospital for medical examination under the guidance of a doctor and actively cooperate with the doctor’s treatment.