Angina attacks vary from person to person. Most people describe it as “chest pressure”, “stuffiness”, “stuffiness”, and some patients feel that it spreads to the shoulders, back, neck, and throat bilaterally, and is relieved by resting or taking nitroglycerin. Symptoms of disease Clinical classification into five types: insidious, angina, myocardial infarction, heart failure (ischemic cardiomyopathy), sudden death. The most common of these is the angina type, and the most serious are the myocardial infarction and sudden death types. Angina pectoris is a group of syndromes due to acute temporary myocardial ischemia, hypoxia: 1, chest pressure and suffocation, stuffiness, severe burning pain, usually pain lasts 1-5 minutes, occasionally up to 15 minutes, can be relieved by themselves. 2, the pain often radiates to the left shoulder, left arm anterior medial up to the little finger and ring finger. 3.Pain occurs when the burden on the heart increases (e.g. increased physical activity, excessive mental stimulation and exposure to cold), and disappears after a few minutes of rest or sublingual nitroglycerin. 4, pain attacks, may be accompanied by (or not accompanied by) weakness, sweating, shortness of breath, anxiety, palpitations, nausea or dizziness. Myocardial infarction is a critical symptom of coronary heart disease, usually have angina attacks frequently and aggravation as the basis, there is no angina history and sudden myocardial infarction cases (this situation is the most dangerous, often due to the lack of defense and cause sudden death). The manifestations of myocardial infarction are: 1, sudden severe pain in the retrosternal or precordial area, radiating to the left shoulder, left arm or other places, and the pain lasts for more than half an hour, which can not be relieved by rest and nitroglycerin. 2, shortness of breath, lightheadedness, and dizziness. Shortness of breath, dizziness, nausea, excessive sweating, and fine pulse. 3.The skin is cold, wet, gray, and seriously ill. 4.About one-tenth of the patients’ only manifestation is syncope or shock.