Coronary heart disease is a common disease among the elderly. So how should coronary heart disease be diagnosed? The diagnosis of coronary heart disease mainly involves the following aspects: First, based on clinical symptoms, patients with coronary heart disease often experience episodes of angina pectoris, which are likely to occur during brisk walking or emotional excitement. Second, electrocardiogram diagnosis; during episodes of angina pectoris, the electrocardiogram often shows changes indicative of myocardial ischemia. Third, coronary angiography, which is a gold standard measure for the definitive diagnosis of coronary heart disease, allows for a clear diagnosis of whether coronary heart disease is present or not. Fourth, the exercise stress test, which can induce episodes of coronary heart disease and also serve as a diagnostic tool for the disease.