Angina pectoris may lead to sudden death. Patients with stable angina tend to survive for a longer period of time, and patients with unstable angina have a certain risk of sudden death due to heart attack. Patients with stable angina can be relieved by stopping activity, resting or taking nitroglycerin. The pain lasts for a short time, usually less than 10 minutes, and tends to flare up with increased activity, intensity of activity or emotional stress. If unstable angina occurs, it can be followed by myocardial infarction. Acute myocardial infarction, if not treated in time, can lead to arrhythmia, ventricular tachycardia, ventricular fibrillation, etc., resulting in sudden death of the patient. Patients with angina pectoris should immediately call 120 for prompt medical attention if they are not relieved after repeatedly taking nitroglycerin and their symptoms continue to worsen, with pain lasting more than half an hour and accompanied by sweating, near-death feeling, shock, syncope and other manifestations.