Stable angina is usually not serious in grades I and II. If it is grade III or IV, it is more serious. Stable angina belongs to a kind of coronary heart disease, which is a clinical syndrome of temporary myocardial ischemia and hypoxia. Determining whether stable angina is serious or not needs to be based on the actual situation and cannot be generalized, but mainly depends on the grading of stable angina. For patients with stable angina of grades I and II, the condition is generally not serious and is relatively stable. However, patients with stable angina of grades III and IV are more serious, mainly because of the risk of acute myocardial infarction or sudden death, as well as the higher degree of cardiac function and coronary artery disease. Most patients with stable angina can survive for many years, and patients need to actively cooperate with doctors to carry out rehabilitation training, which is conducive to the recovery of cardiac function. To summarize, patients with stable angina need to strengthen their daily life management and go to the hospital for regular checkups, so that doctors can understand the changes in their condition.