In the cardiology department, we often encounter patients who visit the doctor for chest pain. Some people have some pain in the chest occasionally and tell the doctor that they have “angina pectoris”, while others have serious symptoms and may be in danger at any time, but they know nothing about it. Today, we will talk to you about the identification of angina. The six characteristics of angina 1, the site of the upper or middle of the sternum, the boundaries are not very clear, often radiating to the left shoulder, the left inner arm up to the ring finger or little finger, or to the neck, throat or jaw. When angina attacks, the patient often has difficulty in expressing the exact location of the pain. 2. The nature of the pain is difficult to describe accurately and is often a feeling of pressure, tightness, or obstructive suffocation rather than true pain. Patients are afraid to continue activities, which is a common characteristic of patients with angina pectoris. 3, emotional changes, physical activity, satiety, cold, smoking, etc. may induce angina, and the possibility of angina attack in the morning is greater than in the afternoon. 4, the duration is often 2-15min, not more than half an hour. Those who last for more than half an hour are less common. However, if the attack of chest pain is very short, instantaneous, and like a pinprick or “lightning-like” pain, most of them are not angina, but may be intercostal neuralgia, or chest discomfort caused by premature heartbeat. 5.Relief can be relieved after stopping the activities that induce the symptoms; sublingual nitroglycerin can be relieved quickly after 2-3 minutes, and it should be noted that nitroglycerin can only contain 1 tablet each time, and if the pain cannot be relieved, it can be repeated every 5 minutes with 1 tablet, and the continuous use cannot exceed 3 tablets. 6, chest pain occurs suddenly. Angina attack chest pain, the patient often little or no aura, in the interval between the two attacks, the patient’s feeling can be completely normal. Therefore, the sudden onset of chest pain is a very important danger signal of angina pectoris. Some patients often confuse chest pain with stomach pain. Generally speaking, stomach pain is often accompanied by acid vomiting and a burning sensation in the upper abdomen, and the pain of stomach pain is predominantly vague. Stomach attacks are closely related to improper eating, while there is no obvious connection with activity, mood swings and mental tension. Not all chest pain is angina Sometimes elderly people cannot describe their condition exactly. Angina needs to be differentiated from cardiac neurosis, pneumothorax, angina caused by other diseases, intercostal neuralgia and biliary and upper gastrointestinal diseases. In addition, angina is not always painful in the heart, some patients have abdominal discomfort or burning sensation and stomach pain as the main symptoms, which is very easy to misdiagnose. The pain caused by general gastric disease often occurs on an empty stomach or after meals, related to eating, and lasts more than half an hour or several days without relief; while the pain caused by heart disease is generally related to exercise, exertion, emotional changes and other factors, and some patients always occur in the middle of the night or early morning, lasting several minutes or more than ten minutes, and can be relieved by rest or medication. Angina originates from the increased load on the heart The pathogenesis of angina is the imbalance between myocardial oxygen demand and supply. Under normal conditions, the coronary circulation has a large reserve power and its blood flow can vary significantly with the physiological condition of the body; during strenuous physical activity, the coronary arteries expand appropriately and the blood flow can increase to 6-7 times that at rest. During hypoxia, coronary arteries also dilate and can increase blood flow by 4-5 times. When the coronary arteries are narrowed or partially occluded due to atherosclerosis, their dilatability is reduced, blood flow is decreased, and the oxygen supply to the myocardium is relatively fixed, so if the blood supply to the myocardium is reduced to the extent that it can still cope with the usual needs of the heart, it can be asymptomatic at rest. Once the heart load suddenly increases, such as exertion, excitement, left heart failure, etc., so that myocardial tension increases, myocardial contraction force increases and heart rate increases, resulting in increased myocardial oxygen consumption, myocardial demand for blood increases, while the coronary blood supply can not be increased accordingly, can cause angina. Warm reminder: angina pectoris is also one of the danger signs of coronary heart disease, especially in patients with frequent attacks or serious degree. Once angina occurs, it means that the condition is more serious and the necessary preventive and control measures should be actively taken.