The main clinical symptom of unstable angina is chest pain, which can be triggered by physical activity, emotional fluctuations, etc., and can also occur at rest. Unstable angina is characterized by an increase in the frequency, severity and duration of chest pain, which can occur at rest or at night, and the degree and extent of chest pain can be aggravated, accompanied by new symptoms, such as sweating, nausea, vomiting, palpitations, or dyspnea, etc. Routine rest or sublingual nitroglycerin can only provide temporary relief of the symptoms, or even not complete relief. Unstable angina is caused by platelet aggregation on the basis of rupture or erosion of unstable atheromatous plaque, complicated by thrombosis, coronary artery spasm and contraction, microvascular embolism leading to acute or subacute reduction of blood supply to the myocardium or aggravation of ischemia, and it is not accompanied by myocardial cell necrosis. To prevent the disease from progressing to acute myocardial infarction, antiplatelet and lipid-modulating drugs are usually required to control the condition. If the symptoms of unstable angina exist for a long time, it is recommended to take medication regularly as prescribed by the doctor, as well as to do a good cardiac physical examination to detect the problem as early as possible to avoid serious consequences.