Whether ischemic heart disease is serious or not depends on the degree of stenosis, the location of the diseased vessel and whether it leads to heart failure. 1. Degree of stenosis: If the degree of stenosis has reached the criteria for stent implantation, and there are obvious signs of ischemia, such as cardiac colic and squeezing pain, this situation is considered serious. If the vessel has multiple stenosis, or diffuse occlusion of the vessel, or there are lesions of multiple large vessels, this situation is more serious. If only a small branch stenosis, ischemic area is relatively small, this situation is not particularly serious, but also to pay enough attention. 2. The location of the diseased blood vessels: the heart has four major blood vessels to supply most of the blood needed by the heart, including the left main stem, anterior descending branch, the rotary branch, and the right coronary artery. If the proximal end of these four major blood vessels is stenotic and the blood supply is insufficient, the situation will be very serious. 3. Whether it leads to heart failure: If ischemic heart disease leads to heart failure, it means it is very serious. If ischemic heart disease occurs, it should be treated actively.