Coronary artery stenosis is graded according to the degree of narrowing of the coronary arteries and is generally divided into four classes. 1. Grade 1: Mild coronary artery stenosis, with a stenosis of less than 25%. 2. Grade 2: A relatively mild coronary artery stenosis with a stenosis of 26%-50%. 3. Grade III: is a moderate coronary artery stenosis with a stenosis of 51%-70%. 4. Grade 4: generally refers to the degree of coronary artery stenosis more than 70%, belonging to the severe coronary artery stenosis, indicating that the symptoms are more serious. If the patient has uncomfortable symptoms should be timely medical treatment, for mild and relatively light coronary artery stenosis, usually need to use drugs under the guidance of the doctor to carry out treatment, if the patient is moderate or severe coronary artery stenosis, usually need to carry out surgical treatment. It is recommended to consult a doctor in time for relevant examinations, according to the specific situation, under the guidance of the doctor, to carry out symptomatic treatment.