First aid in case of angina pectoris is as follows: 1. rest in bed and calm down; 2. you can take nitroglycerin under the tongue, if the symptoms can be relieved, you need to continue to observe and clarify whether there are recurrent attacks. If the symptoms recur, you need to seek medical attention. Repeated nitroglycerin may cause a drop in blood pressure, resulting in serious consequences. Therefore, if the symptoms recur, you should avoid taking nitroglycerin continuously, and you need to call 120 to the hospital in time. 3. After arriving at the hospital, you need to conduct electrocardiogram examination and blood test to further evaluate the cause of chest pain through relevant examination. If angina pectoris is considered as coronary artery disease, oral anti-platelet aggregation drugs and subcutaneous injection of low-molecular heparin for anticoagulation therapy are also required. In case of recurrent symptoms, percutaneous coronary angiography and, if necessary, stenting will be performed.