Angina pectoris is an acute attack symptom caused by coronary heart disease. Angina is often triggered by a narrowing of the coronary vessels and reduced blood flow due to coronary atherosclerosis, when the heart burden is increased by exertion, exercise, emotional stress, straining to defecate, etc. When angina attacks, the patient will suddenly feel a persistent crushing or suffocating pain under the sternum. Patients first immediately stop all activities, calm down, can rest in place, without lying down, so as not to increase the amount of blood return and thus increase the burden on the heart. Immediately take out the first-aid medicine with you, such as a piece of nitroglycerin, chew it and put it under the tongue, usually the pain can be relieved in about two minutes. If the effect is not good, you can take another one under the tongue after 10 minutes. However, it should be noted that it is not advisable to take more than three nitroglycerin tablets in a row, regardless of whether the angina is relieved, or if there is another attack. If the pain is not relieved, call an ambulance to the hospital immediately. For people with coronary artery disease who have a first attack of angina, they will fall into extreme panic because of the sudden severe pain in the heart, which is very detrimental to the relief of angina, and the panic will obviously speed up the heart rate, thus increasing the burden on the heart. Patients with first-onset angina, often do not carry emergency drugs, encounter this situation do not have to worry too much about the danger, most of the angina attack lasts less than 10 minutes, in the absence of drugs, stop activities in place to rest, maintain a calm state of mind, is the most effective first aid measures. If the pain is not relieved, go to the hospital immediately.