Aspirin was first discovered as a class of antipyretic, analgesic and anti-inflammatory drugs, and is currently the most widely used anti-platelet aggregation drug. At higher applied doses, it has antipyretic and analgesic effects and can be used for toothache, headache, rheumatism, etc. In small doses it is an anti-platelet aggregation drug and is useful in preventing blood clots. It can be used for the treatment and prevention of cerebral infarction and transient ischemic attack. Its main side effects include: it may cause bleeding, especially gastrointestinal bleeding or allergy, asthma, etc.