The diagnosis of angina is confirmed as follows: 1. Diagnosis is made by whether the patient has the corresponding symptoms, such as whether there is exertional chest pain, shortness of breath, chest discomfort, etc.; 2. Diagnosis is confirmed by whether the patient has susceptibility factors, such as whether there is high blood pressure, diabetes, high blood fats, whether he stays up late or drinks heavily; 3. Diagnosis is confirmed by objective index tests, such as by laboratory tests of blood lipids, liver function, kidney function, and the need to understand whether there is myocardial ischaemia through electrocardiogram, which can be done through X-ray, cardiac ultrasound to understand whether the heart is enlarged, and through coronary angiogram to directly show whether there is narrowing of the coronary arteries, resulting in insufficient blood supply to the heart muscle.