Carotid artery stenosis of 90% is more serious and may lead to serious cerebrovascular events, followed by neurological deficits such as hemiparesis, aphasia, and even life-threatening conditions. Stenosis greater than 70% is usually considered an indication for surgery, and more than 50% with clinical symptoms is also an indication for surgery. If not actively intervened, the carotid artery on this side may be completely occluded, which may lead to partial infarction of the cerebral hemisphere on the same side, causing hemiparesis and hemiplegia on the opposite side of the limb, and if it is the dominant hemisphere, it may also cause speech dysfunction. At the same time, if the infarction area is large and the cerebral edema is serious, it may also cause cerebral hernia, which is life-threatening. Therefore, carotid artery stenosis 90%, should be timely medical treatment, under the guidance of the doctor to intervene in the treatment.