Aspirin is a drug commonly used in clinical practice. It has two pharmacological effects, one of which is antipyretic and analgesic, that is, antipyretic and anti-inflammatory. It is mainly used for febrile diseases, especially rheumatic fever. The other action is anti-platelet aggregation, which is mainly used for the prevention and treatment of ischemic cardiovascular diseases. For example, coronary heart disease, myocardial infarction, cerebral infarction, sclerosis of cerebral blood vessels, etc. It should be noted that it exerts two different effects and requires different doses. For antipyretic and analgesic, a larger dose is needed, for example, 300-500 mg, while for antiplatelet aggregation, the dosage is generally smaller, 50-150 mg/day, but long-term use is needed. The main side effects of aspirin, in large doses for long term use may be peptic ulcers, bleeding from the gastrointestinal tract, or even perforation of the gastrointestinal tract. Due to the effect of aspirin on the blood clotting system, nosebleeds, bleeding from teeth, coughing up blood, blood in urine and bleeding under the skin may occur during the administration of the drug.